diff --git a/CHANGES b/CHANGES
index 3293709613..83997fc6bc 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,7 @@
+5.0.0-dev.462 | 2022-05-19 11:45:38 -0700
+
+  * speed up ZAM compilation by capping function size when inlining (Vern Paxson, Corelight)
+
 5.0.0-dev.460 | 2022-05-19 11:24:50 -0700
 
   * Zeekify the scripts.base.utils.paths test (Christian Kreibich, Corelight)
diff --git a/VERSION b/VERSION
index 266c3be4d5..c81e4ef5cf 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-5.0.0-dev.460
+5.0.0-dev.462
diff --git a/src/Expr.cc b/src/Expr.cc
index fa3dfaafdf..98fcb637ec 100644
--- a/src/Expr.cc
+++ b/src/Expr.cc
@@ -110,10 +110,13 @@ const char* expr_name(BroExprTag t)
 	return expr_names[int(t)];
 	}
 
+int Expr::num_exprs = 0;
+
 Expr::Expr(BroExprTag arg_tag) : tag(arg_tag), paren(false), type(nullptr)
 	{
 	SetLocationInfo(&start_location, &end_location);
 	opt_info = new ExprOptInfo();
+	++num_exprs;
 	}
 
 Expr::~Expr()
diff --git a/src/Expr.h b/src/Expr.h
index f6e45561a7..d000d88538 100644
--- a/src/Expr.h
+++ b/src/Expr.h
@@ -406,6 +406,12 @@ public:
 	// this statement.
 	ExprOptInfo* GetOptInfo() const { return opt_info; }
 
+	// Returns the number of expressions created since the last reset.
+	static int GetNumExprs() { return num_exprs; }
+
+	// Clears the number of expressions created.
+	static void ResetNumExprs() { num_exprs = 0; }
+
 	~Expr() override;
 
 protected:
@@ -441,6 +447,9 @@ protected:
 	// Information associated with the Expr for purposes of
 	// script optimization.
 	ExprOptInfo* opt_info;
+
+	// Number of expressions created thus far.
+	static int num_exprs;
 	};
 
 class NameExpr final : public Expr
diff --git a/src/Stmt.cc b/src/Stmt.cc
index 00d29e8eb6..0c1265fbfb 100644
--- a/src/Stmt.cc
+++ b/src/Stmt.cc
@@ -59,6 +59,8 @@ const char* stmt_name(StmtTag t)
 	return stmt_names[int(t)];
 	}
 
+int Stmt::num_stmts = 0;
+
 Stmt::Stmt(StmtTag arg_tag)
 	{
 	tag = arg_tag;
@@ -69,6 +71,8 @@ Stmt::Stmt(StmtTag arg_tag)
 	opt_info = new StmtOptInfo();
 
 	SetLocationInfo(&start_location, &end_location);
+
+	++num_stmts;
 	}
 
 Stmt::~Stmt()
diff --git a/src/StmtBase.h b/src/StmtBase.h
index 58683e6767..d70cf8b0aa 100644
--- a/src/StmtBase.h
+++ b/src/StmtBase.h
@@ -177,6 +177,12 @@ public:
 	// this statement.
 	StmtOptInfo* GetOptInfo() const { return opt_info; }
 
+	// Returns the number of statements created since the last reset.
+	static int GetNumStmts() { return num_stmts; }
+
+	// Clears the number of statements created.
+	static void ResetNumStmts() { num_stmts = 0; }
+
 protected:
 	explicit Stmt(StmtTag arg_tag);
 
@@ -203,6 +209,9 @@ protected:
 	// Information associated with the Stmt for purposes of
 	// script optimization.
 	StmtOptInfo* opt_info;
+
+	// Number of statements created thus far.
+	static int num_stmts;
 	};
 
 	} // namespace detail
diff --git a/src/Var.cc b/src/Var.cc
index dba0e620fb..35b37ac56b 100644
--- a/src/Var.cc
+++ b/src/Var.cc
@@ -718,6 +718,10 @@ void begin_func(IDPtr id, const char* module_name, FunctionFlavor flavor, bool i
 
 	if ( Attr* depr_attr = find_attr(current_scope()->Attrs().get(), ATTR_DEPRECATED) )
 		current_scope()->GetID()->MakeDeprecated(depr_attr->GetExpr());
+
+	// Reset the AST node statistics to track afresh for this function.
+	Stmt::ResetNumStmts();
+	Expr::ResetNumExprs();
 	}
 
 class OuterIDBindingFinder : public TraversalCallback
@@ -804,7 +808,10 @@ void end_func(StmtPtr body, bool free_of_conditionals)
 		// by duplicating can itself be correctly duplicated.
 		body = body->Duplicate()->Duplicate();
 
-	body->GetOptInfo()->is_free_of_conditionals = free_of_conditionals;
+	auto oi = body->GetOptInfo();
+	oi->is_free_of_conditionals = free_of_conditionals;
+	oi->num_stmts = Stmt::GetNumStmts();
+	oi->num_exprs = Expr::GetNumExprs();
 
 	auto ingredients = std::make_unique<function_ingredients>(pop_scope(), std::move(body));
 
diff --git a/src/script_opt/Expr.cc b/src/script_opt/Expr.cc
index b76f4b16bd..47eac78351 100644
--- a/src/script_opt/Expr.cc
+++ b/src/script_opt/Expr.cc
@@ -2329,6 +2329,10 @@ ExprPtr CallExpr::Inline(Inliner* inl)
 	{
 	auto new_me = inl->CheckForInlining({NewRef{}, this});
 
+	if ( ! new_me )
+		// All done with inlining.
+		return ThisPtr();
+
 	if ( new_me.get() != this )
 		return new_me;
 
diff --git a/src/script_opt/Inline.cc b/src/script_opt/Inline.cc
index f9b3e12fd5..cc2ed52100 100644
--- a/src/script_opt/Inline.cc
+++ b/src/script_opt/Inline.cc
@@ -5,10 +5,13 @@
 #include "zeek/Desc.h"
 #include "zeek/script_opt/ProfileFunc.h"
 #include "zeek/script_opt/ScriptOpt.h"
+#include "zeek/script_opt/StmtOptInfo.h"
 
 namespace zeek::detail
 	{
 
+constexpr int MAX_INLINE_SIZE = 1000;
+
 void Inliner::Analyze()
 	{
 	// Locate self- and indirectly recursive functions.
@@ -139,8 +142,15 @@ void Inliner::InlineFunction(FuncInfo* f)
 	// particular body.
 	curr_frame_size = f->Scope()->Length();
 
+	auto oi = f->Body()->GetOptInfo();
+	num_stmts = oi->num_stmts;
+	num_exprs = oi->num_exprs;
+
 	f->Body()->Inline(this);
 
+	oi->num_stmts = num_stmts;
+	oi->num_exprs = num_exprs;
+
 	int new_frame_size = curr_frame_size + max_inlined_frame_size;
 
 	if ( new_frame_size > f->Func()->FrameSize() )
@@ -175,9 +185,19 @@ ExprPtr Inliner::CheckForInlining(CallExprPtr c)
 	if ( inline_ables.count(func_vf) == 0 )
 		return c;
 
-	ListExprPtr args = {NewRef{}, c->Args()};
+	// We're going to inline the body, unless it's too large.
 	auto body = func_vf->GetBodies()[0].stmts; // there's only 1 body
-	auto t = c->GetType();
+	auto oi = body->GetOptInfo();
+
+	if ( num_stmts + oi->num_stmts + num_exprs + oi->num_exprs > MAX_INLINE_SIZE )
+		return nullptr;
+
+	num_stmts += oi->num_stmts;
+	num_exprs += oi->num_exprs;
+
+	auto body_dup = body->Duplicate();
+	body_dup->GetOptInfo()->num_stmts = oi->num_stmts;
+	body_dup->GetOptInfo()->num_exprs = oi->num_exprs;
 
 	// Getting the names of the parameters is tricky.  It's tempting
 	// to take them from the function's type declaration, but alas
@@ -198,8 +218,6 @@ ExprPtr Inliner::CheckForInlining(CallExprPtr c)
 	for ( int i = 0; i < nparam; ++i )
 		params.emplace_back(vars[i]);
 
-	auto body_dup = body->Duplicate();
-
 	// Recursively inline the body.  This is safe to do because we've
 	// ensured there are no recursive loops ... but we have to be
 	// careful in accounting for the frame sizes.
@@ -221,6 +239,8 @@ ExprPtr Inliner::CheckForInlining(CallExprPtr c)
 	else
 		max_inlined_frame_size = hold_max_inlined_frame_size;
 
+	ListExprPtr args = {NewRef{}, c->Args()};
+	auto t = c->GetType();
 	auto ie = make_intrusive<InlineExpr>(args, std::move(params), body_dup, curr_frame_size, t);
 	ie->SetOriginal(c);
 
diff --git a/src/script_opt/Inline.h b/src/script_opt/Inline.h
index 3b8d24b9c7..738096c919 100644
--- a/src/script_opt/Inline.h
+++ b/src/script_opt/Inline.h
@@ -27,8 +27,8 @@ public:
 		Analyze();
 		}
 
-	// Either returns the original CallExpr if it's not inline-able,
-	// or an InlineExpr if it is.
+	// Either returns the original CallExpr if it's not inline-able;
+	// or an InlineExpr if it is; or nil if further inlining should stop.
 	ExprPtr CheckForInlining(CallExprPtr c);
 
 	// True if the given function has been inlined.
@@ -57,6 +57,12 @@ protected:
 	// prior to increasing it to accommodate inlining.
 	int curr_frame_size;
 
+	// The number of statements and expressions in the function being
+	// inlined.  Dynamically updated as the inlining proceeds.  Used
+	// to cap inlining complexity.
+	int num_stmts;
+	int num_exprs;
+
 	// Whether to generate a report about functions either directly and
 	// indirectly recursive.
 	bool report_recursive;
diff --git a/src/script_opt/StmtOptInfo.h b/src/script_opt/StmtOptInfo.h
index 449ecc0e61..cbc9eae4da 100644
--- a/src/script_opt/StmtOptInfo.h
+++ b/src/script_opt/StmtOptInfo.h
@@ -26,6 +26,10 @@ public:
 	// Whether this statement is free of the possible influence
 	// of conditional code.
 	bool is_free_of_conditionals = true;
+
+	// Number of statements and expressions in a function body.
+	int num_stmts = 0;
+	int num_exprs = 0;
 	};
 
 	} // namespace zeek::detail
diff --git a/testing/btest/Baseline.zam/coverage.coverage-blacklist/output b/testing/btest/Baseline.zam/coverage.coverage-blacklist/output
index 863a383031..d54a7d5645 100644
--- a/testing/btest/Baseline.zam/coverage.coverage-blacklist/output
+++ b/testing/btest/Baseline.zam/coverage.coverage-blacklist/output
@@ -1,6 +1,10 @@
 ### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
 0	<...>/coverage-blacklist.zeek, line 13	print cover me;
+0	<...>/coverage-blacklist.zeek, line 15	if (T)   print always executed; 
 0	<...>/coverage-blacklist.zeek, line 17	print always executed;
+0	<...>/coverage-blacklist.zeek, line 22	if (F)   print impossible; 
+0	<...>/coverage-blacklist.zeek, line 24	if (F)   print also impossible, but included in code coverage analysis; 
 0	<...>/coverage-blacklist.zeek, line 26	print also impossible, but included in code coverage analysis;
 0	<...>/coverage-blacklist.zeek, line 29	print success;
 0	<...>/coverage-blacklist.zeek, line 5	print first;
+0	<...>/coverage-blacklist.zeek, line 7	if (F)   {   print hello;  print world;  } 
diff --git a/testing/btest/Baseline.zam/language.type-cast-error-dynamic/err b/testing/btest/Baseline.zam/language.type-cast-error-dynamic/err
index 36890af23b..16bde5304a 100644
--- a/testing/btest/Baseline.zam/language.type-cast-error-dynamic/err
+++ b/testing/btest/Baseline.zam/language.type-cast-error-dynamic/err
@@ -1,4 +1,4 @@
 ### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
 runtime error in <...>/type-cast-error-dynamic.zeek, line 12: invalid cast of value with type 'count' to type 'string'
 runtime error in <...>/type-cast-error-dynamic.zeek, line 12: invalid cast of value with type 'record { a:addr; b:port; }' to type 'string'
-runtime error in <...>/type-cast-error-dynamic.zeek, line 12: invalid cast of value with type 'record { data:opaque of Broker::Data &optional; }' to type 'string' (nil $data field)
+runtime error in <...>/type-cast-error-dynamic.zeek, line 12: invalid cast of value with type 'Broker::Data' to type 'string' (nil $data field)
diff --git a/testing/btest/scripts/base/frameworks/netcontrol/basic-cluster.zeek b/testing/btest/scripts/base/frameworks/netcontrol/basic-cluster.zeek
index 55bc9776db..6dd28aa1e8 100644
--- a/testing/btest/scripts/base/frameworks/netcontrol/basic-cluster.zeek
+++ b/testing/btest/scripts/base/frameworks/netcontrol/basic-cluster.zeek
@@ -9,7 +9,7 @@
 
 # @TEST-EXEC: btest-bg-run worker-2  "cp ../cluster-layout.zeek . && CLUSTER_NODE=worker-2 zeek -b --pseudo-realtime -C -r $TRACES/tls/ecdhe.pcap %INPUT"
 # This timeout needs to be large to accommodate ZAM compilation delays.
-# @TEST-EXEC: btest-bg-wait 90
+# @TEST-EXEC: btest-bg-wait 45
 # @TEST-EXEC: btest-diff worker-1/.stdout
 # @TEST-EXEC: btest-diff worker-2/.stdout
 
diff --git a/testing/btest/scripts/base/frameworks/sumstats/sample-cluster.zeek b/testing/btest/scripts/base/frameworks/sumstats/sample-cluster.zeek
index c190df57ea..ec1524e7a5 100644
--- a/testing/btest/scripts/base/frameworks/sumstats/sample-cluster.zeek
+++ b/testing/btest/scripts/base/frameworks/sumstats/sample-cluster.zeek
@@ -1,7 +1,3 @@
-# the scripts and triggers the timeout.  Ultimately we need to address this
-# by capping the size of inlined functions, since the main delay comes from
-# traversing enormous AST function bodies.
-# @TEST-REQUIRES: test "${ZEEK_ZAM}" != "1"
 # @TEST-PORT: BROKER_PORT1
 # @TEST-PORT: BROKER_PORT2
 # @TEST-PORT: BROKER_PORT3
@@ -10,7 +6,7 @@
 # @TEST-EXEC: btest-bg-run worker-1  ZEEKPATH=$ZEEKPATH:.. CLUSTER_NODE=worker-1 zeek -b %INPUT
 # @TEST-EXEC: btest-bg-run worker-2  ZEEKPATH=$ZEEKPATH:.. CLUSTER_NODE=worker-2 zeek -b %INPUT
 # This timeout needs to be large to accommodate ZAM compilation delays.
-# @TEST-EXEC: btest-bg-wait 90
+# @TEST-EXEC: btest-bg-wait 45
 # @TEST-EXEC: TEST_DIFF_CANONIFIER=$SCRIPTS/diff-sort btest-diff manager-1/.stdout
 
 @load base/frameworks/sumstats