diff --git a/CHANGES b/CHANGES
index 19f23b713a..32d1d7edf9 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,25 @@
+7.1.0-dev.687 | 2024-12-05 21:43:49 +0100
+
+  * ZAM documentation updates for asserts and event handler run-time errors (Vern Paxson, Corelight)
+
+  * BTest updates for ZAM support of (optionally) keeping "assert" statements (Vern Paxson, Corelight)
+
+  * command-line options for controlling script optimization: keeping asserts, (Vern Paxson, Corelight)
+    avoiding event handler coalescence
+
+  * ZAM support for option to not coalesce event handlers (Vern Paxson, Corelight)
+
+  * ZAM support for keeping "assert" statements (Vern Paxson, Corelight)
+
+  * internal support for script optimization options for keeping asserts, not (Vern Paxson, Corelight)
+    consolidating event handlers
+
+  * ZAM operations to support asserts (Vern Paxson, Corelight)
+
+  * simplified "assert" by not trying to catch messages that themselves have errors (Vern Paxson, Corelight)
+
+  * ZAM optimization now removes hook calls to hooks without any bodies (Vern Paxson, Corelight)
+
 7.1.0-dev.676 | 2024-12-05 11:08:55 -0700
 
   * update of BTest that tracks number of (and validates) ZAM operations (Vern Paxson, Corelight)
diff --git a/VERSION b/VERSION
index cb94f6c958..a69764eb5b 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-7.1.0-dev.676
+7.1.0-dev.687
diff --git a/src/Options.cc b/src/Options.cc
index 25f78e1da8..fc7a639e61 100644
--- a/src/Options.cc
+++ b/src/Options.cc
@@ -192,7 +192,9 @@ static void print_analysis_help() {
     fprintf(stderr, "    dump-final-ZAM	dump final generated ZAM code; implies gen-ZAM-code\n");
     fprintf(stderr, "    gen-ZAM-code	generate ZAM code (without turning on additional optimizations)\n");
     fprintf(stderr, "    inline	inline function calls\n");
+    fprintf(stderr, "    keep-asserts	do not optimize away \"assert\" statements\n");
     fprintf(stderr, "    no-inline	turn off inlining\n");
+    fprintf(stderr, "    no-event-handler-coalescence	when inlining, do not coalescence event handlers\n");
     fprintf(stderr, "    no-ZAM-opt	omit low-level ZAM optimization\n");
     fprintf(stderr, "    optimize-all	optimize all scripts, even inlined ones\n");
     fprintf(stderr, "    optimize-AST	optimize the (transformed) AST; implies xform\n");
@@ -243,8 +245,12 @@ static void set_analysis_option(const char* opt, Options& opts) {
         a_o.activate = a_o.gen_ZAM_code = true;
     else if ( util::streq(opt, "inline") )
         a_o.inliner = true;
+    else if ( util::streq(opt, "keep-asserts") )
+        a_o.keep_asserts = true;
     else if ( util::streq(opt, "no-inline") )
         a_o.no_inliner = true;
+    else if ( util::streq(opt, "no-event-handler-coalescence") )
+        a_o.no_eh_coalescence = true;
     else if ( util::streq(opt, "no-ZAM-opt") )
         a_o.activate = a_o.no_ZAM_opt = true;
     else if ( util::streq(opt, "optimize-all") )
diff --git a/src/Stmt.cc b/src/Stmt.cc
index 7eab80a640..47e839e189 100644
--- a/src/Stmt.cc
+++ b/src/Stmt.cc
@@ -1570,10 +1570,10 @@ TraversalCode NullStmt::Traverse(TraversalCallback* cb) const {
     HANDLE_TC_STMT_POST(tc);
 }
 
-AssertStmt::AssertStmt(ExprPtr arg_cond, ExprPtr arg_msg)
-    : Stmt(STMT_ASSERT), cond(std::move(arg_cond)), msg(std::move(arg_msg)) {
-    if ( ! IsBool(cond->GetType()->Tag()) )
-        cond->Error("conditional must be boolean");
+AssertStmt::AssertStmt(ExprPtr cond, ExprPtr arg_msg)
+    : ExprStmt(STMT_ASSERT, std::move(cond)), msg(std::move(arg_msg)) {
+    if ( ! IsBool(e->GetType()->Tag()) )
+        e->Error("conditional must be boolean");
 
     if ( msg && ! IsString(msg->GetType()->Tag()) )
         msg->Error("message must be string");
@@ -1581,7 +1581,7 @@ AssertStmt::AssertStmt(ExprPtr arg_cond, ExprPtr arg_msg)
     zeek::ODesc desc;
     desc.SetShort(true);
     desc.SetQuotes(true);
-    cond->Describe(&desc);
+    e->Describe(&desc);
 
     cond_desc = desc.Description();
 }
@@ -1592,28 +1592,16 @@ ValPtr AssertStmt::Exec(Frame* f, StmtFlowType& flow) {
 
     static auto assertion_result_hook = id::find_func("assertion_result");
     bool run_result_hook = assertion_result_hook && assertion_result_hook->HasEnabledBodies();
-    auto assert_result = cond->Eval(f)->AsBool();
+    auto assert_result = e->Eval(f)->AsBool();
 
     if ( ! assert_result || run_result_hook ) {
         zeek::StringValPtr msg_val = zeek::val_mgr->EmptyString();
 
-        if ( msg ) {
-            // Eval() may fail if expression assumes assert
-            // condition is F, but we still try to get it for
-            // the assertion_result hook.
-            try {
-                msg_val = cast_intrusive<zeek::StringVal>(msg->Eval(f));
-            } catch ( InterpreterException& e ) {
-                static ODesc desc;
-                desc.Clear();
-                desc.SetShort(true);
-                desc.SetQuotes(true);
-                desc.Add("<error eval ");
-                msg->Describe(&desc);
-                desc.Add(">");
-                msg_val = zeek::make_intrusive<zeek::StringVal>(desc.Len(), (const char*)desc.Bytes());
-            }
-        }
+        if ( msg )
+            // It's up to the script writing to assure that the expression
+            // works regardless of the state of the condition. If they
+            // fail to do so, they can get an exception at this point.
+            msg_val = cast_intrusive<zeek::StringVal>(msg->Eval(f));
 
         report_assert(assert_result, cond_desc, msg_val, GetLocationInfo());
     }
@@ -1631,7 +1619,13 @@ void AssertStmt::StmtDescribe(ODesc* d) const {
     auto orig_quotes = d->WantQuotes();
     d->SetQuotes(true);
 
-    cond->Describe(d);
+    e->Describe(d);
+
+    if ( msg_setup_stmt ) {
+        d->Add("{ ");
+        msg_setup_stmt->Describe(d);
+        d->Add(" }");
+    }
 
     if ( msg ) {
         d->Add(",");
@@ -1648,9 +1642,14 @@ TraversalCode AssertStmt::Traverse(TraversalCallback* cb) const {
     TraversalCode tc = cb->PreStmt(this);
     HANDLE_TC_STMT_PRE(tc);
 
-    tc = cond->Traverse(cb);
+    tc = e->Traverse(cb);
     HANDLE_TC_STMT_PRE(tc);
     if ( msg ) {
+        if ( msg_setup_stmt ) {
+            tc = msg_setup_stmt->Traverse(cb);
+            HANDLE_TC_STMT_PRE(tc);
+        }
+
         tc = msg->Traverse(cb);
         HANDLE_TC_STMT_PRE(tc);
     }
diff --git a/src/Stmt.h b/src/Stmt.h
index d714a61d56..9fac25752e 100644
--- a/src/Stmt.h
+++ b/src/Stmt.h
@@ -495,15 +495,15 @@ private:
     bool is_directive;
 };
 
-class AssertStmt final : public Stmt {
+class AssertStmt final : public ExprStmt {
 public:
     explicit AssertStmt(ExprPtr cond, ExprPtr msg = nullptr);
 
     ValPtr Exec(Frame* f, StmtFlowType& flow) override;
 
-    const auto& Cond() const { return cond; }
     const auto& CondDesc() const { return cond_desc; }
     const auto& Msg() const { return msg; }
+    const auto& MsgSetupStmt() const { return msg_setup_stmt; }
 
     void StmtDescribe(ODesc* d) const override;
 
@@ -516,9 +516,12 @@ public:
     StmtPtr DoReduce(Reducer* c) override;
 
 private:
-    ExprPtr cond;
     std::string cond_desc;
     ExprPtr msg;
+
+    // Statement to execute before evaluating "msg". Only used for script
+    // optimization.
+    StmtPtr msg_setup_stmt;
 };
 
 // Helper function for reporting on asserts that either failed, or should
diff --git a/src/script_opt/CPP/Stmts.cc b/src/script_opt/CPP/Stmts.cc
index fadb8e989a..ace13e4e24 100644
--- a/src/script_opt/CPP/Stmts.cc
+++ b/src/script_opt/CPP/Stmts.cc
@@ -480,7 +480,7 @@ void CPPCompile::GenForOverString(const ExprPtr& str, const IDPList* loop_vars)
 }
 
 void CPPCompile::GenAssertStmt(const AssertStmt* a) {
-    auto& cond = a->Cond();
+    auto cond = a->StmtExpr();
     auto& msg = a->Msg();
 
     Emit("{ // begin a new scope for internal \"assert\" variables");
diff --git a/src/script_opt/Inline.cc b/src/script_opt/Inline.cc
index ad727dd908..30fef7d415 100644
--- a/src/script_opt/Inline.cc
+++ b/src/script_opt/Inline.cc
@@ -166,7 +166,8 @@ void Inliner::Analyze() {
         inline_ables[func] = f.Profile();
     }
 
-    CoalesceEventHandlers();
+    if ( ! analysis_options.no_eh_coalescence )
+        CoalesceEventHandlers();
 
     for ( auto& f : funcs )
         if ( f.ShouldAnalyze() )
diff --git a/src/script_opt/ScriptOpt.cc b/src/script_opt/ScriptOpt.cc
index 47effda307..60347c876b 100644
--- a/src/script_opt/ScriptOpt.cc
+++ b/src/script_opt/ScriptOpt.cc
@@ -265,11 +265,13 @@ static void init_options() {
     check_env_opt("ZEEK_DUMP_UDS", analysis_options.dump_uds);
     check_env_opt("ZEEK_INLINE", analysis_options.inliner);
     check_env_opt("ZEEK_NO_INLINE", analysis_options.no_inliner);
+    check_env_opt("ZEEK_NO_EH_COALESCENCE", analysis_options.no_eh_coalescence);
     check_env_opt("ZEEK_OPT", analysis_options.optimize_AST);
     check_env_opt("ZEEK_XFORM", analysis_options.activate);
     check_env_opt("ZEEK_ZAM", analysis_options.gen_ZAM);
     check_env_opt("ZEEK_COMPILE_ALL", analysis_options.compile_all);
     check_env_opt("ZEEK_REPORT_UNCOMPILABLE", analysis_options.report_uncompilable);
+    check_env_opt("ZEEK_ZAM_KEEP_ASSERTS", analysis_options.keep_asserts);
     check_env_opt("ZEEK_ZAM_CODE", analysis_options.gen_ZAM_code);
     check_env_opt("ZEEK_NO_ZAM_OPT", analysis_options.no_ZAM_opt);
     check_env_opt("ZEEK_NO_ZAM_CONTROL_FLOW_OPT", analysis_options.no_ZAM_control_flow_opt);
diff --git a/src/script_opt/ScriptOpt.h b/src/script_opt/ScriptOpt.h
index 441c8d6ec2..de537af785 100644
--- a/src/script_opt/ScriptOpt.h
+++ b/src/script_opt/ScriptOpt.h
@@ -57,6 +57,12 @@ struct AnalyOpt {
     // enabled due to other options.
     bool no_inliner = false;
 
+    // If true, when inlining skip event handler coalescence.
+    bool no_eh_coalescence = false;
+
+    // Whether to keep or elide "assert" statements.
+    bool keep_asserts = false;
+
     // If true, report which functions are directly and indirectly
     // recursive, and exit.  Only germane if running the inliner.
     bool report_recursive = false;
diff --git a/src/script_opt/Stmt.cc b/src/script_opt/Stmt.cc
index 95ef0a5cec..01c9a21e77 100644
--- a/src/script_opt/Stmt.cc
+++ b/src/script_opt/Stmt.cc
@@ -1069,11 +1069,36 @@ StmtPtr InitStmt::DoReduce(Reducer* c) {
     return ThisPtr();
 }
 
-StmtPtr AssertStmt::Duplicate() { return SetSucc(new AssertStmt(cond->Duplicate(), msg ? msg->Duplicate() : nullptr)); }
+StmtPtr AssertStmt::Duplicate() { return SetSucc(new AssertStmt(e->Duplicate(), msg ? msg->Duplicate() : nullptr)); }
 
-bool AssertStmt::IsReduced(Reducer* c) const { return false; }
+bool AssertStmt::IsReduced(Reducer* c) const {
+    if ( ! analysis_options.keep_asserts )
+        return false;
 
-StmtPtr AssertStmt::DoReduce(Reducer* c) { return TransformMe(make_intrusive<NullStmt>(), c); }
+    return e->IsSingleton(c) && (! msg || msg->IsSingleton(c));
+}
+
+StmtPtr AssertStmt::DoReduce(Reducer* c) {
+    if ( ! analysis_options.keep_asserts )
+        return TransformMe(make_intrusive<NullStmt>(), c);
+
+    if ( c->Optimizing() ) {
+        e = c->OptExpr(e);
+        if ( msg )
+            msg = c->OptExpr(msg);
+        return ThisPtr();
+    }
+    else if ( IsReduced(c) )
+        return ThisPtr();
+
+    StmtPtr red_stmt;
+    e = e->ReduceToSingleton(c, red_stmt);
+    if ( msg )
+        msg = msg->ReduceToSingleton(c, msg_setup_stmt);
+
+    auto sl = with_location_of(make_intrusive<StmtList>(red_stmt, ThisPtr()), this);
+    return sl->Reduce(c);
+}
 
 bool WhenInfo::HasUnreducedIDs(Reducer* c) const {
     for ( auto& cp : *cl ) {
diff --git a/src/script_opt/UseDefs.cc b/src/script_opt/UseDefs.cc
index e0edc9a85b..ad238e6dcb 100644
--- a/src/script_opt/UseDefs.cc
+++ b/src/script_opt/UseDefs.cc
@@ -287,6 +287,21 @@ UDs UseDefs::PropagateUDs(const Stmt* s, UDs succ_UDs, const Stmt* succ_stmt, bo
             return CreateUDs(s, uds);
         }
 
+        case STMT_ASSERT: {
+            auto a = s->AsAssertStmt();
+            auto e = a->StmtExpr();
+
+            if ( auto msg = a->Msg().get() ) {
+                succ_UDs = UD_Union(succ_UDs, ExprUDs(msg));
+                if ( auto msg_setup_stmt = a->MsgSetupStmt().get() ) {
+                    succ_UDs = PropagateUDs(msg_setup_stmt, succ_UDs, succ_stmt, second_pass);
+                    succ_stmt = msg_setup_stmt;
+                }
+            }
+
+            return CreateUDs(s, UD_Union(succ_UDs, ExprUDs(e)));
+        }
+
         case STMT_SWITCH: {
             auto sw_UDs = std::make_shared<UseDefSet>();
 
diff --git a/src/script_opt/ZAM/OPs/stmts.op b/src/script_opt/ZAM/OPs/stmts.op
index 37d99b6c71..f90ee75237 100644
--- a/src/script_opt/ZAM/OPs/stmts.op
+++ b/src/script_opt/ZAM/OPs/stmts.op
@@ -337,3 +337,33 @@ macro BuildWhen(zf, timeout)
 			local_aggrs.push_back(v);
 		}
 	(void)make_intrusive<trigger::Trigger>(wi, wi->WhenExprGlobals(), local_aggrs, timeout, Z_FRAME, Z_LOC->Loc());
+
+# Helper instruction that loads into $$ a boolean indicating whether an
+# upcoming assertion should be reported.
+op Should-Report-Assert
+classes VV
+op-types I I
+eval	static auto assertion_result_hook = id::find_func("assertion_result");
+	bool run_result_hook = assertion_result_hook && assertion_result_hook->HasEnabledBodies();
+	$$ = ! $1 || run_result_hook;
+
+op Report-Assert
+# Operands are (1) result from Should-Report-Assert, (2) assertion value,
+# (3) description of the condition (always a constant).
+op1-read
+classes VVC
+op-types I I S
+eval	if ( $$ )
+		{
+		zeek::StringValPtr msg_val = zeek::val_mgr->EmptyString();
+		report_assert($1, $2->ToStdString(), msg_val, Z_LOC->Loc());
+		}
+
+op Report-Assert-With-Message
+# The same, but with an additional operand being the associated message
+# (as a variable, so it comes in $2 rather than $3).
+op1-read
+classes VVVC
+op-types I I S S
+eval	if ( $$ )
+		report_assert($1, $3->ToStdString(), {NewRef{}, $2}, Z_LOC->Loc());
diff --git a/src/script_opt/ZAM/README.md b/src/script_opt/ZAM/README.md
index 103bb2a971..d9c598ef47 100644
--- a/src/script_opt/ZAM/README.md
+++ b/src/script_opt/ZAM/README.md
@@ -70,7 +70,14 @@ variables.
 
 ### Incompatibilities:
 
-* ZAM ignores `assert` statements.
+* By default, ZAM removes `assert` statements (including any side effects
+present in their elements). To keep these, specify `-O keep-asserts`.
+
+* For event handlers with multiple bodies, if one of the bodies encounters
+a run-time error, the later (lower priority) bodies won't run, because ZAM
+inlines all of the bodies together to facilitate cross-body optimization.
+If you need full isolation between event handler bodies, you can specify
+`-O no-event-handler-coalescence` to turning off the inlining.
 
 * The `same_object()` BiF will always deem two non-container values as
 different.
@@ -94,7 +101,9 @@ issues:
 |`gen-ZAM-code`		|	Generate ZAM without additional optimizations.|
 |`help`		|	Print this list.|
 |`inline`		|	Inline function calls.|
+|`keep-asserts`		|	Don't optimize away `assert` statements.|
 |`no-inline`		|	Suppress inlining even if another option implies it.|
+|`no-event-handler-coalescence`		|	When inlining, do not coalescence event handlers.|
 |`no-ZAM-opt`	|	Turn off low-level ZAM optimization.|
 |`optimize-all`	|	Optimize all scripts, even inlined ones. You need to separately specify which optimizations you want to apply, e.g., `-O inline -O xform`.|
 |`optimize-AST`	|	Optimize the (transform) AST; implies `xform`.|
diff --git a/src/script_opt/ZAM/Stmt.cc b/src/script_opt/ZAM/Stmt.cc
index 65a9d94e13..75075dfa86 100644
--- a/src/script_opt/ZAM/Stmt.cc
+++ b/src/script_opt/ZAM/Stmt.cc
@@ -48,6 +48,8 @@ const ZAMStmt ZAMCompiler::CompileStmt(const Stmt* s) {
 
         case STMT_WHEN: return CompileWhen(static_cast<const WhenStmt*>(s));
 
+        case STMT_ASSERT: return CompileAssert(static_cast<const AssertStmt*>(s));
+
         case STMT_NULL: return EmptyStmt();
 
         case STMT_CHECK_ANY_LEN: {
@@ -1047,6 +1049,45 @@ const ZAMStmt ZAMCompiler::CompileWhen(const WhenStmt* ws) {
     return AddInst(z);
 }
 
+const ZAMStmt ZAMCompiler::CompileAssert(const AssertStmt* as) {
+    auto cond = as->StmtExpr();
+
+    int cond_slot;
+    if ( cond->Tag() == EXPR_CONST )
+        cond_slot = TempForConst(cond->AsConstExpr());
+    else
+        cond_slot = FrameSlot(cond->AsNameExpr());
+
+    auto decision_slot = NewSlot(false);
+
+    (void)AddInst(ZInstI(OP_SHOULD_REPORT_ASSERT_VV, decision_slot, cond_slot));
+
+    ZInstI z;
+
+    // We don't have a convenient way of directly introducing a std::string
+    // constant, so we build one to hold it.
+    auto cond_desc = make_intrusive<StringVal>(new String(as->CondDesc()));
+    auto cond_desc_e = make_intrusive<ConstExpr>(cond_desc);
+
+    if ( auto msg = as->Msg() ) {
+        auto& msg_setup_stmt = as->MsgSetupStmt();
+        if ( msg_setup_stmt )
+            (void)CompileStmt(msg_setup_stmt);
+
+        int msg_slot;
+        if ( msg->Tag() == EXPR_CONST )
+            msg_slot = TempForConst(msg->AsConstExpr());
+        else
+            msg_slot = FrameSlot(msg->AsNameExpr());
+
+        z = ZInstI(OP_REPORT_ASSERT_WITH_MESSAGE_VVVC, decision_slot, cond_slot, msg_slot, cond_desc_e.get());
+    }
+    else
+        z = ZInstI(OP_REPORT_ASSERT_VVC, decision_slot, cond_slot, cond_desc_e.get());
+
+    return AddInst(z);
+}
+
 const ZAMStmt ZAMCompiler::InitRecord(IDPtr id, RecordType* rt) {
     auto z = ZInstI(OP_INIT_RECORD_V, FrameSlot(id));
     z.SetType({NewRef{}, rt});
diff --git a/src/script_opt/ZAM/Stmt.h b/src/script_opt/ZAM/Stmt.h
index 8a85ed4539..242fbe8197 100644
--- a/src/script_opt/ZAM/Stmt.h
+++ b/src/script_opt/ZAM/Stmt.h
@@ -20,6 +20,7 @@ const ZAMStmt CompileCatchReturn(const CatchReturnStmt* cr);
 const ZAMStmt CompileStmts(const StmtList* sl);
 const ZAMStmt CompileInit(const InitStmt* is);
 const ZAMStmt CompileWhen(const WhenStmt* ws);
+const ZAMStmt CompileAssert(const AssertStmt* ws);
 
 const ZAMStmt CompileNext() { return GenGoTo(nexts.back()); }
 const ZAMStmt CompileBreak() { return GenGoTo(breaks.back()); }
diff --git a/src/script_opt/ZAM/Vars.h b/src/script_opt/ZAM/Vars.h
index 5fe46e9fe4..affc88ec69 100644
--- a/src/script_opt/ZAM/Vars.h
+++ b/src/script_opt/ZAM/Vars.h
@@ -25,8 +25,8 @@ int FrameSlotIfName(const Expr* e) {
     return n ? FrameSlot(n->Id()) : -1;
 }
 
-int FrameSlot(const NameExpr* id) { return FrameSlot(id->AsNameExpr()->Id()); }
-int Frame1Slot(const NameExpr* id, ZOp op) { return Frame1Slot(id->AsNameExpr()->Id(), op); }
+int FrameSlot(const NameExpr* n) { return FrameSlot(n->Id()); }
+int Frame1Slot(const NameExpr* n, ZOp op) { return Frame1Slot(n->Id(), op); }
 
 int Frame1Slot(const ID* id, ZOp op) { return Frame1Slot(id, op1_flavor[op]); }
 int Frame1Slot(const NameExpr* n, ZAMOp1Flavor fl) { return Frame1Slot(n->Id(), fl); }
diff --git a/testing/btest/Baseline.zam/language.assert-2/out b/testing/btest/Baseline.zam/language.assert-2/out
new file mode 100644
index 0000000000..40ed4ca014
--- /dev/null
+++ b/testing/btest/Baseline.zam/language.assert-2/out
@@ -0,0 +1,3 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+error in <...>/assert.zeek, line 3: assertion failure: fmt("%s", 1) == "2" ("1" != "2")
+fatal error: errors occurred while initializing
diff --git a/testing/btest/Baseline.zam/language.assert-3/out b/testing/btest/Baseline.zam/language.assert-3/out
new file mode 100644
index 0000000000..5a58147fa5
--- /dev/null
+++ b/testing/btest/Baseline.zam/language.assert-3/out
@@ -0,0 +1,3 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+error in <...>/assert.zeek, line 3: assertion failure: (coerce to_count("42") to double) == 42.5 (always failing)
+fatal error: errors occurred while initializing
diff --git a/testing/btest/Baseline.zam/language.assert-4/out b/testing/btest/Baseline.zam/language.assert-4/out
new file mode 100644
index 0000000000..3146002d53
--- /dev/null
+++ b/testing/btest/Baseline.zam/language.assert-4/out
@@ -0,0 +1,3 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+error in <...>/assert.zeek, line 4: assertion failure: 1 == x (Expected x to be 1, have 2)
+fatal error: errors occurred while initializing
diff --git a/testing/btest/Baseline.zam/language.assert-5/out b/testing/btest/Baseline.zam/language.assert-5/out
new file mode 100644
index 0000000000..166362e0c3
--- /dev/null
+++ b/testing/btest/Baseline.zam/language.assert-5/out
@@ -0,0 +1,6 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+error in <...>/assert.zeek, line 9: assertion failure: "ghi" in tbl ({
+	[abc] = 123,
+	[def] = 456
+})
+fatal error: errors occurred while initializing
diff --git a/testing/btest/Baseline.zam/language.assert-6/out b/testing/btest/Baseline.zam/language.assert-6/out
new file mode 100644
index 0000000000..e400085e57
--- /dev/null
+++ b/testing/btest/Baseline.zam/language.assert-6/out
@@ -0,0 +1,3 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+runtime error in <...>/assert.zeek, line 9: field value missing: $b
+fatal error: errors occurred while initializing
diff --git a/testing/btest/Baseline.zam/language.assert-7/out b/testing/btest/Baseline.zam/language.assert-7/out
new file mode 100644
index 0000000000..e400085e57
--- /dev/null
+++ b/testing/btest/Baseline.zam/language.assert-7/out
@@ -0,0 +1,3 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+runtime error in <...>/assert.zeek, line 9: field value missing: $b
+fatal error: errors occurred while initializing
diff --git a/testing/btest/Baseline.zam/language.assert-8/out b/testing/btest/Baseline.zam/language.assert-8/out
new file mode 100644
index 0000000000..7d877b65b5
--- /dev/null
+++ b/testing/btest/Baseline.zam/language.assert-8/out
@@ -0,0 +1,3 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+error in <...>/assert.zeek, line 2: assertion failure: 1 == 2 (always false)
+fatal error: failed to execute script statements at top-level scope
diff --git a/testing/btest/Baseline.zam/language.assert-error-2/.stderr b/testing/btest/Baseline.zam/language.assert-error-2/.stderr
new file mode 100644
index 0000000000..ffba84808c
--- /dev/null
+++ b/testing/btest/Baseline.zam/language.assert-error-2/.stderr
@@ -0,0 +1,2 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+error in <...>/assert-error.zeek, line 3: message must be string (1234)
diff --git a/testing/btest/Baseline.zam/language.assert-error-3/.stderr b/testing/btest/Baseline.zam/language.assert-error-3/.stderr
new file mode 100644
index 0000000000..8bbc43e570
--- /dev/null
+++ b/testing/btest/Baseline.zam/language.assert-error-3/.stderr
@@ -0,0 +1,2 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+error in <...>/assert-error.zeek, line 3: syntax error, at or near ";"
diff --git a/testing/btest/Baseline.zam/language.assert-error-4/.stderr b/testing/btest/Baseline.zam/language.assert-error-4/.stderr
new file mode 100644
index 0000000000..90ff2d507a
--- /dev/null
+++ b/testing/btest/Baseline.zam/language.assert-error-4/.stderr
@@ -0,0 +1,2 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+error in <...>/assert-error.zeek, line 3: syntax error, at or near ","
diff --git a/testing/btest/Baseline.zam/language.assert-error/.stderr b/testing/btest/Baseline.zam/language.assert-error/.stderr
new file mode 100644
index 0000000000..1f636a5228
--- /dev/null
+++ b/testing/btest/Baseline.zam/language.assert-error/.stderr
@@ -0,0 +1,2 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+error in <...>/assert-error.zeek, line 8: conditional must be boolean (1)
diff --git a/testing/btest/Baseline.zam/language.assert-hook-2/.stderr b/testing/btest/Baseline.zam/language.assert-hook-2/.stderr
new file mode 100644
index 0000000000..49d861c74c
--- /dev/null
+++ b/testing/btest/Baseline.zam/language.assert-hook-2/.stderr
@@ -0,0 +1 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
diff --git a/testing/btest/Baseline.zam/language.assert-hook-2/out b/testing/btest/Baseline.zam/language.assert-hook-2/out
new file mode 100644
index 0000000000..32d490fa18
--- /dev/null
+++ b/testing/btest/Baseline.zam/language.assert-hook-2/out
@@ -0,0 +1,4 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+assertion_failure, to_count("5") == 4, 5 is not 4
+assert <...>/assert-hook.zeek:21
+ zeek_init <none>:0
diff --git a/testing/btest/Baseline.zam/language.assert-hook-3/.stderr b/testing/btest/Baseline.zam/language.assert-hook-3/.stderr
new file mode 100644
index 0000000000..a1707e3408
--- /dev/null
+++ b/testing/btest/Baseline.zam/language.assert-hook-3/.stderr
@@ -0,0 +1,3 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+error in <...>/assert-hook.zeek, line 12: assertion failure: F (terminate me!)
+received termination signal
diff --git a/testing/btest/Baseline.zam/language.assert-hook-3/out b/testing/btest/Baseline.zam/language.assert-hook-3/out
new file mode 100644
index 0000000000..a09aae6630
--- /dev/null
+++ b/testing/btest/Baseline.zam/language.assert-hook-3/out
@@ -0,0 +1,3 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+assertion_failure, terminate me!
+zeek_done()
diff --git a/testing/btest/Baseline.zam/language.assert-hook-4/.stderr b/testing/btest/Baseline.zam/language.assert-hook-4/.stderr
new file mode 100644
index 0000000000..49d861c74c
--- /dev/null
+++ b/testing/btest/Baseline.zam/language.assert-hook-4/.stderr
@@ -0,0 +1 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
diff --git a/testing/btest/Baseline.zam/language.assert-hook-4/out b/testing/btest/Baseline.zam/language.assert-hook-4/out
new file mode 100644
index 0000000000..13dabea91e
--- /dev/null
+++ b/testing/btest/Baseline.zam/language.assert-hook-4/out
@@ -0,0 +1,2 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+assertion_failure, calling exit!
diff --git a/testing/btest/Baseline.zam/language.assert-hook-5/.stderr b/testing/btest/Baseline.zam/language.assert-hook-5/.stderr
new file mode 100644
index 0000000000..49d861c74c
--- /dev/null
+++ b/testing/btest/Baseline.zam/language.assert-hook-5/.stderr
@@ -0,0 +1 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
diff --git a/testing/btest/Baseline.zam/language.assert-hook-5/out b/testing/btest/Baseline.zam/language.assert-hook-5/out
new file mode 100644
index 0000000000..cfd12f766e
--- /dev/null
+++ b/testing/btest/Baseline.zam/language.assert-hook-5/out
@@ -0,0 +1,8 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+assertion_result T at <...>/assert-hook.zeek:25: md5_hash("") == "d41d8cd98f00b204e9800998ecf8427e"
+assertion_result T at <...>/assert-hook.zeek:30: sha1_hash("") == "da39a3ee5e6b4b0d3255bfef95601890afd80709"
+assertion_result F at <...>/assert-hook.zeek:35: sha1_hash("") == "wrong"
+assertion_failure at <...>/assert-hook.zeek:35: sha1_hash("") == "wrong"
+assertion_result F at <...>/assert-hook.zeek:40: md5_hash("") == "wrong"
+assertion_failure at <...>/assert-hook.zeek:40: md5_hash("") == "wrong"
+2 of 4 assertions failed
diff --git a/testing/btest/Baseline.zam/language.assert-hook-6/.stderr b/testing/btest/Baseline.zam/language.assert-hook-6/.stderr
new file mode 100644
index 0000000000..c63e318d97
--- /dev/null
+++ b/testing/btest/Baseline.zam/language.assert-hook-6/.stderr
@@ -0,0 +1,3 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+runtime error in <...>/assert-hook.zeek, line 18: field value missing: $ip
+error in <...>/assert-hook.zeek, line 24: assertion failure: 2 + 2 == 5 ({"msg":"false and works"})
diff --git a/testing/btest/Baseline.zam/language.assert-hook-6/out b/testing/btest/Baseline.zam/language.assert-hook-6/out
new file mode 100644
index 0000000000..19ff952797
--- /dev/null
+++ b/testing/btest/Baseline.zam/language.assert-hook-6/out
@@ -0,0 +1,4 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+assertion_result, T, 2 + 2 == 4, {"msg":"true and works"}, <...>/assert-hook.zeek, 15
+assertion_result, F, 2 + 2 == 5, {"msg":"false and works"}, <...>/assert-hook.zeek, 24
+assertion_failure, 2 + 2 == 5, {"msg":"false and works"}, <...>/assert-hook.zeek, 24
diff --git a/testing/btest/Baseline.zam/language.assert-hook-7/.stderr b/testing/btest/Baseline.zam/language.assert-hook-7/.stderr
new file mode 100644
index 0000000000..49d861c74c
--- /dev/null
+++ b/testing/btest/Baseline.zam/language.assert-hook-7/.stderr
@@ -0,0 +1 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
diff --git a/testing/btest/Baseline.zam/language.assert-hook-7/out b/testing/btest/Baseline.zam/language.assert-hook-7/out
new file mode 100644
index 0000000000..820b6a66a1
--- /dev/null
+++ b/testing/btest/Baseline.zam/language.assert-hook-7/out
@@ -0,0 +1,5 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+assertion_result, T, 2 + 2 == 4, this is true, <...>/assert-hook.zeek, 10
+assertion_result, T, 2 + 2 == 4, {"msg":"this is also true"}, <...>/assert-hook.zeek, 11
+assertion_result, F, 2 + 2 == 5, this is false, <...>/assert-hook.zeek, 12
+assertion_result, F, 2 + 2 == 5, this is false, <...>/assert-hook.zeek, 18
diff --git a/testing/btest/Baseline.zam/language.assert-hook-8/.stderr b/testing/btest/Baseline.zam/language.assert-hook-8/.stderr
new file mode 100644
index 0000000000..49d861c74c
--- /dev/null
+++ b/testing/btest/Baseline.zam/language.assert-hook-8/.stderr
@@ -0,0 +1 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
diff --git a/testing/btest/Baseline.zam/language.assert-hook-8/out b/testing/btest/Baseline.zam/language.assert-hook-8/out
new file mode 100644
index 0000000000..01f1c34267
--- /dev/null
+++ b/testing/btest/Baseline.zam/language.assert-hook-8/out
@@ -0,0 +1,6 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+zeek_init
+returning true
+assertion_result, T, always_true(), always true, <...>/assert-hook.zeek, 23
+returning false
+assertion_result, F, always_false(), always false, <...>/assert-hook.zeek, 24
diff --git a/testing/btest/Baseline.zam/language.assert-hook/.stderr b/testing/btest/Baseline.zam/language.assert-hook/.stderr
new file mode 100644
index 0000000000..70a0f9c3a1
--- /dev/null
+++ b/testing/btest/Baseline.zam/language.assert-hook/.stderr
@@ -0,0 +1,2 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+error in <...>/assert-hook.zeek, line 15: assertion failure: 1 != 1
diff --git a/testing/btest/Baseline.zam/language.assert-hook/out b/testing/btest/Baseline.zam/language.assert-hook/out
new file mode 100644
index 0000000000..f92c1a466f
--- /dev/null
+++ b/testing/btest/Baseline.zam/language.assert-hook/out
@@ -0,0 +1,2 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+assertion_failure, 1 != 1, , <...>/assert-hook.zeek, 15
diff --git a/testing/btest/Baseline.zam/language.assert-misc/out b/testing/btest/Baseline.zam/language.assert-misc/out
new file mode 100644
index 0000000000..b53a1c6bf7
--- /dev/null
+++ b/testing/btest/Baseline.zam/language.assert-misc/out
@@ -0,0 +1,7 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+f, lambda_<10820400278317158366>: function() : void
+ZAM-code lambda_<10820400278317158366>
+g, lambda_<9730512750166342063>: function() : void
+ZAM-code lambda_<9730512750166342063>
+test_function, test_function: function() : void
+ZAM-code test_function
diff --git a/testing/btest/Baseline.zam/language.assert/out b/testing/btest/Baseline.zam/language.assert/out
new file mode 100644
index 0000000000..256b93f1c8
--- /dev/null
+++ b/testing/btest/Baseline.zam/language.assert/out
@@ -0,0 +1,3 @@
+### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+error in <...>/assert.zeek, line 8: assertion failure: fmt("%s", 1) == "2"
+fatal error: errors occurred while initializing
diff --git a/testing/btest/Baseline.zam/opt.validate-ZAM/output b/testing/btest/Baseline.zam/opt.validate-ZAM/output
index 1707dacb53..ab1e22adfe 100644
--- a/testing/btest/Baseline.zam/opt.validate-ZAM/output
+++ b/testing/btest/Baseline.zam/opt.validate-ZAM/output
@@ -1,2 +1,2 @@
 ### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
-1245 valid, 1883 tested, 437 skipped
+1248 valid, 1892 tested, 437 skipped
diff --git a/testing/btest/Baseline/language.assert-7/out b/testing/btest/Baseline/language.assert-7/out
index c28e697ecb..9008a99cda 100644
--- a/testing/btest/Baseline/language.assert-7/out
+++ b/testing/btest/Baseline/language.assert-7/out
@@ -1,4 +1,3 @@
 ### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
-expression error in <...>/assert.zeek, line 10: field value missing (r$b)
-error in <...>/assert.zeek, line 10: assertion failure: r?$b (<error eval fmt("r$b is not set trying anyway: %s", r$b)>)
+expression error in <...>/assert.zeek, line 12: field value missing (r$b)
 fatal error: errors occurred while initializing
diff --git a/testing/btest/Baseline/language.assert-hook-6/.stderr b/testing/btest/Baseline/language.assert-hook-6/.stderr
index 13dbb41dae..08f2a26abf 100644
--- a/testing/btest/Baseline/language.assert-hook-6/.stderr
+++ b/testing/btest/Baseline/language.assert-hook-6/.stderr
@@ -1,5 +1,3 @@
 ### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
-expression error in <...>/assert-hook.zeek, line 15: field value missing (get_current_packet_header()$ip)
-expression error in <...>/assert-hook.zeek, line 17: field value missing (get_current_packet_header()$ip)
-error in <...>/assert-hook.zeek, line 17: assertion failure: 2 + 2 == 5 (<error eval cat(get_current_packet_header()$ip)>)
-error in <...>/assert-hook.zeek, line 22: assertion failure: 2 + 2 == 5 ({"msg":"false and works"})
+expression error in <...>/assert-hook.zeek, line 18: field value missing (get_current_packet_header()$ip)
+error in <...>/assert-hook.zeek, line 24: assertion failure: 2 + 2 == 5 ({"msg":"false and works"})
diff --git a/testing/btest/Baseline/language.assert-hook-6/out b/testing/btest/Baseline/language.assert-hook-6/out
index 37d07df4b9..19ff952797 100644
--- a/testing/btest/Baseline/language.assert-hook-6/out
+++ b/testing/btest/Baseline/language.assert-hook-6/out
@@ -1,7 +1,4 @@
 ### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
-assertion_result, T, 2 + 2 == 4, <error eval cat(get_current_packet_header()$ip)>, <...>/assert-hook.zeek, 15
-assertion_result, T, 2 + 2 == 4, {"msg":"true and works"}, <...>/assert-hook.zeek, 16
-assertion_result, F, 2 + 2 == 5, <error eval cat(get_current_packet_header()$ip)>, <...>/assert-hook.zeek, 17
-assertion_failure, 2 + 2 == 5, <error eval cat(get_current_packet_header()$ip)>, <...>/assert-hook.zeek, 17
-assertion_result, F, 2 + 2 == 5, {"msg":"false and works"}, <...>/assert-hook.zeek, 22
-assertion_failure, 2 + 2 == 5, {"msg":"false and works"}, <...>/assert-hook.zeek, 22
+assertion_result, T, 2 + 2 == 4, {"msg":"true and works"}, <...>/assert-hook.zeek, 15
+assertion_result, F, 2 + 2 == 5, {"msg":"false and works"}, <...>/assert-hook.zeek, 24
+assertion_failure, 2 + 2 == 5, {"msg":"false and works"}, <...>/assert-hook.zeek, 24
diff --git a/testing/btest/Baseline/language.assert-hook/.stderr b/testing/btest/Baseline/language.assert-hook/.stderr
index c04263e182..70a0f9c3a1 100644
--- a/testing/btest/Baseline/language.assert-hook/.stderr
+++ b/testing/btest/Baseline/language.assert-hook/.stderr
@@ -1,2 +1,2 @@
 ### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
-error in <...>/assert-hook.zeek, line 18: assertion failure: 1 != 1
+error in <...>/assert-hook.zeek, line 15: assertion failure: 1 != 1
diff --git a/testing/btest/Baseline/language.assert-hook/out b/testing/btest/Baseline/language.assert-hook/out
index f4efbf3732..f92c1a466f 100644
--- a/testing/btest/Baseline/language.assert-hook/out
+++ b/testing/btest/Baseline/language.assert-hook/out
@@ -1,2 +1,2 @@
 ### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
-assertion_failure, 1 != 1, , <...>/assert-hook.zeek, 18
+assertion_failure, 1 != 1, , <...>/assert-hook.zeek, 15
diff --git a/testing/btest/Baseline/language.assert-top-level/.stderr b/testing/btest/Baseline/language.assert-top-level/.stderr
index 5322f47419..18c84b3171 100644
--- a/testing/btest/Baseline/language.assert-top-level/.stderr
+++ b/testing/btest/Baseline/language.assert-top-level/.stderr
@@ -1,3 +1,3 @@
 ### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
-error in <...>/assert-top-level.zeek, line 7: assertion failure: getpid() == 0 (my pid greater 0? T)
+error in <...>/assert-top-level.zeek, line 5: assertion failure: getpid() == 0 (my pid greater 0? T)
 fatal error: failed to execute script statements at top-level scope
diff --git a/testing/btest/Baseline/language.assert/out b/testing/btest/Baseline/language.assert/out
index 886324ae99..256b93f1c8 100644
--- a/testing/btest/Baseline/language.assert/out
+++ b/testing/btest/Baseline/language.assert/out
@@ -1,3 +1,3 @@
 ### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
-error in <...>/assert.zeek, line 11: assertion failure: fmt("%s", 1) == "2"
+error in <...>/assert.zeek, line 8: assertion failure: fmt("%s", 1) == "2"
 fatal error: errors occurred while initializing
diff --git a/testing/btest/btest.cfg b/testing/btest/btest.cfg
index 405ad41f3c..7116aff382 100644
--- a/testing/btest/btest.cfg
+++ b/testing/btest/btest.cfg
@@ -99,4 +99,5 @@ BTEST_BASELINE_DIR=%(testbase)s/Baseline.cpp:%(testbase)s/Baseline
 # (no -j).
 [environment-zam]
 ZEEK_ZAM=1
+ZEEK_ZAM_KEEP_ASSERTS=1
 BTEST_BASELINE_DIR=%(testbase)s/Baseline.zam:%(testbase)s/Baseline.xform:%(testbase)s/Baseline
diff --git a/testing/btest/language/assert-hook.zeek b/testing/btest/language/assert-hook.zeek
index 1f107ff70e..e43ed368c9 100644
--- a/testing/btest/language/assert-hook.zeek
+++ b/testing/btest/language/assert-hook.zeek
@@ -1,9 +1,6 @@
 # @TEST-DOC: Assert statement testing with assertion_failure and assertion_result implementation.
 #
-# Doesn't make sense for ZAM as it ignores assert's.
-# @TEST-REQUIRES: test "${ZEEK_ZAM}" != "1"
-#
-# @TEST-EXEC: zeek -b %INPUT >out
+# @TEST-EXEC: zeek -b -O no-event-handler-coalescence %INPUT >out
 # @TEST-EXEC: TEST_DIFF_CANONIFIER=$SCRIPTS/diff-remove-abspath btest-diff out
 # @TEST-EXEC: TEST_DIFF_CANONIFIER=$SCRIPTS/diff-remove-abspath btest-diff .stderr
 
@@ -164,9 +161,11 @@ hook assertion_result(result: bool, cond: string, msg: string, bt: Backtrace)
 
 event zeek_init()
 	{
-	assert 2 + 2 == 4, cat(get_current_packet_header()$ip);
 	assert 2 + 2 == 4, to_json([$msg="true and works"]);
-	assert 2 + 2 == 5, cat(get_current_packet_header()$ip);
+	# This next assert will generate a run-time error, exiting the
+	# event handler.
+	assert 2 + 2 == 4, cat(get_current_packet_header()$ip);
+	assert 2 + 2 == 5, "didn't get to here";
 	}
 
 event zeek_done()
diff --git a/testing/btest/language/assert-misc.zeek b/testing/btest/language/assert-misc.zeek
index 6c9de58432..5a70a532dc 100644
--- a/testing/btest/language/assert-misc.zeek
+++ b/testing/btest/language/assert-misc.zeek
@@ -1,9 +1,6 @@
 # @TEST-DOC: Test Describe() of assert statement. Expressions may be canonicalized.
 #
-# Doesn't make sense for ZAM as it ignores assert's.
-# @TEST-REQUIRES: test "${ZEEK_ZAM}" != "1"
-#
-# @TEST-EXEC: zeek -b %INPUT >out 2>&1
+# @TEST-EXEC: zeek -b -O no-event-handler-coalescence %INPUT >out 2>&1
 # @TEST-EXEC: TEST_DIFF_CANONIFIER=$SCRIPTS/diff-remove-abspath btest-diff out
 
 function test_function()
diff --git a/testing/btest/language/assert-top-level.zeek b/testing/btest/language/assert-top-level.zeek
index 0bde1ad926..738beca071 100644
--- a/testing/btest/language/assert-top-level.zeek
+++ b/testing/btest/language/assert-top-level.zeek
@@ -1,5 +1,3 @@
-# Doesn't make sense for ZAM as it ignores assert's.
-# @TEST-REQUIRES: test "${ZEEK_ZAM}" != "1"
 # @TEST-EXEC-FAIL: zeek -b %INPUT >out
 # @TEST-EXEC: TEST_DIFF_CANONIFIER=$SCRIPTS/diff-remove-abspath btest-diff .stderr
 
diff --git a/testing/btest/language/assert.zeek b/testing/btest/language/assert.zeek
index 79ea8a9096..c79918c353 100644
--- a/testing/btest/language/assert.zeek
+++ b/testing/btest/language/assert.zeek
@@ -1,9 +1,6 @@
 # @TEST-DOC: Assert statement behavior testing without an assertion_failure() hook.
 #
-# Doesn't make sense for ZAM as it ignores assert's.
-# @TEST-REQUIRES: test "${ZEEK_ZAM}" != "1"
-#
-# @TEST-EXEC-FAIL: unset ZEEK_ALLOW_INIT_ERRORS; zeek -b %INPUT >out 2>&1
+# @TEST-EXEC-FAIL: unset ZEEK_ALLOW_INIT_ERRORS; zeek -b -O no-event-handler-coalescence %INPUT >out 2>&1
 # @TEST-EXEC: TEST_DIFF_CANONIFIER=$SCRIPTS/diff-remove-abspath btest-diff out
 
 event zeek_init()
@@ -69,6 +66,8 @@ event zeek_init()
 	{
 	local r: MyRecord = [$a=1234];
 	assert ! r?$b, fmt("Unexpected r$b is set to %s", r$b);
+	# This will generate a run-time error, rather than reporting the
+	# failed assertion.
 	assert r?$b, fmt("r$b is not set trying anyway: %s", r$b);
 	}
 
diff --git a/testing/btest/language/type-cast-error-dynamic-ZAM.zeek b/testing/btest/language/type-cast-error-dynamic-ZAM.zeek
index 73f6b48549..8527d3c899 100644
--- a/testing/btest/language/type-cast-error-dynamic-ZAM.zeek
+++ b/testing/btest/language/type-cast-error-dynamic-ZAM.zeek
@@ -1,4 +1,4 @@
-# @TEST-REQUIRES: test "${ZEEK_ZAM}" == "1"
+# @TEST-REQUIRES: test "${ZEEK_ZAM}" = "1"
 # @TEST-EXEC-FAIL: zeek -b %INPUT >output 2>err
 # @TEST-EXEC: TEST_DIFF_CANONIFIER=$SCRIPTS/diff-remove-abspath btest-diff err
 
diff --git a/testing/btest/language/uninitialized-local.ZAM.zeek b/testing/btest/language/uninitialized-local.ZAM.zeek
index d41f3431df..c67716f455 100644
--- a/testing/btest/language/uninitialized-local.ZAM.zeek
+++ b/testing/btest/language/uninitialized-local.ZAM.zeek
@@ -1,5 +1,5 @@
 # A version of uninitialized-local.zeek suitable for ZAM's behavior.
-# @TEST-REQUIRES: test "${ZEEK_ZAM}" == "1"
+# @TEST-REQUIRES: test "${ZEEK_ZAM}" = "1"
 # @TEST-EXEC-FAIL: zeek -b %INPUT >out 2>&1
 
 event testit() &priority=10
diff --git a/testing/btest/opt/AST-side-effects.zeek b/testing/btest/opt/AST-side-effects.zeek
index bb204c40f7..01d20624f0 100644
--- a/testing/btest/opt/AST-side-effects.zeek
+++ b/testing/btest/opt/AST-side-effects.zeek
@@ -1,5 +1,5 @@
 # @TEST-DOC: Stress tests for the AST optimizer dealing with side effects.
-# @TEST-REQUIRES: test "${ZEEK_ZAM}" == "1"
+# @TEST-REQUIRES: test "${ZEEK_ZAM}" = "1"
 #
 # See below for an explanation of this convoluted invocation line.
 # @TEST-EXEC: zeek -b -O ZAM -O dump-xform --optimize-func='AST_opt_test_.*' %INPUT >output
diff --git a/testing/btest/opt/ZAM-bif-tracking.zeek b/testing/btest/opt/ZAM-bif-tracking.zeek
index e173410674..627c21f444 100644
--- a/testing/btest/opt/ZAM-bif-tracking.zeek
+++ b/testing/btest/opt/ZAM-bif-tracking.zeek
@@ -1,5 +1,5 @@
 # @TEST-DOC: ZAM maintenance script for tracking changes in BiFs.
-# @TEST-REQUIRES: test "${ZEEK_ZAM}" == "1"
+# @TEST-REQUIRES: test "${ZEEK_ZAM}" = "1"
 #
 # @TEST-EXEC: zeek -b %INPUT >output
 # @TEST-EXEC: btest-diff output
diff --git a/testing/btest/opt/validate-ZAM.zeek b/testing/btest/opt/validate-ZAM.zeek
index 2640581f58..d2798b1d8d 100644
--- a/testing/btest/opt/validate-ZAM.zeek
+++ b/testing/btest/opt/validate-ZAM.zeek
@@ -1,5 +1,5 @@
 # @TEST-DOC: ZAM maintenance script for validating synthesized operations.
-# @TEST-REQUIRES: test "${ZEEK_ZAM}" == "1"
+# @TEST-REQUIRES: test "${ZEEK_ZAM}" = "1"
 #
 # @TEST-EXEC: zeek -b -O validate-ZAM %INPUT >output
 # @TEST-EXEC: btest-diff output