diff --git a/src/Expr.cc b/src/Expr.cc
index 7b33a141d8..4912c1c1c0 100644
--- a/src/Expr.cc
+++ b/src/Expr.cc
@@ -272,7 +272,7 @@ IntrusivePtr<Expr> NameExpr::MakeLvalue()
 void NameExpr::Assign(Frame* f, IntrusivePtr<Val> v)
 	{
 	if ( id->IsGlobal() )
-		id->SetVal(v.release());
+		id->SetVal(std::move(v));
 	else
 		f->SetElement(id.get(), v.release());
 	}
@@ -4241,10 +4241,10 @@ LambdaExpr::LambdaExpr(std::unique_ptr<function_ingredients> arg_ing,
 	// Update lamb's name
 	dummy_func->SetName(my_name.c_str());
 
-	Val* v = new Val(dummy_func);
+	auto v = make_intrusive<Val>(dummy_func);
 	Unref(dummy_func);
-	id->SetVal(v); // id will unref v when its done.
-	id->SetType(ingredients->id->Type()->Ref());
+	id->SetVal(std::move(v));
+	id->SetType({NewRef{}, ingredients->id->Type()});
 	id->SetConst();
 	}
 
diff --git a/src/Func.cc b/src/Func.cc
index 5583032f79..58652c8217 100644
--- a/src/Func.cc
+++ b/src/Func.cc
@@ -613,7 +613,7 @@ BuiltinFunc::BuiltinFunc(built_in_func arg_func, const char* arg_name,
 		reporter->InternalError("built-in function %s multiply defined", Name());
 
 	type = id->Type()->Ref();
-	id->SetVal(new Val(this));
+	id->SetVal(make_intrusive<Val>(this));
 	}
 
 BuiltinFunc::~BuiltinFunc()
diff --git a/src/ID.cc b/src/ID.cc
index 2eea08acfa..2355962fb6 100644
--- a/src/ID.cc
+++ b/src/ID.cc
@@ -26,9 +26,7 @@ ID::ID(const char* arg_name, IDScope arg_scope, bool arg_is_export)
 	scope = arg_scope;
 	is_export = arg_is_export;
 	is_option = false;
-	type = 0;
 	val = 0;
-	attrs = 0;
 	is_const = false;
 	is_enum_const = false;
 	is_type = false;
@@ -43,11 +41,6 @@ ID::ID(const char* arg_name, IDScope arg_scope, bool arg_is_export)
 ID::~ID()
 	{
 	delete [] name;
-	Unref(type);
-	Unref(attrs);
-
-	for ( auto element : option_handlers )
-		Unref(element.second);
 
 	if ( ! weak_ref )
 		Unref(val);
@@ -58,9 +51,9 @@ string ID::ModuleName() const
 	return extract_module_name(name);
 	}
 
-void ID::SetType(BroType* t)
+void ID::SetType(IntrusivePtr<BroType> t)
 	{
-	Unref(type); type = t;
+	type = std::move(t);
 	}
 
 void ID::ClearVal()
@@ -71,12 +64,12 @@ void ID::ClearVal()
 	val = 0;
 	}
 
-void ID::SetVal(Val* v, bool arg_weak_ref)
+void ID::SetVal(IntrusivePtr<Val> v, bool arg_weak_ref)
 	{
 	if ( ! weak_ref )
 		Unref(val);
 
-	val = v;
+	val = v.release();
 	weak_ref = arg_weak_ref;
 	Modified();
 
@@ -104,11 +97,11 @@ void ID::SetVal(Val* v, bool arg_weak_ref)
 		}
 	}
 
-void ID::SetVal(Val* v, init_class c)
+void ID::SetVal(IntrusivePtr<Val> v, init_class c)
 	{
 	if ( c == INIT_NONE || c == INIT_FULL )
 		{
-		SetVal(v);
+		SetVal(std::move(v));
 		return;
 		}
 
@@ -117,9 +110,9 @@ void ID::SetVal(Val* v, init_class c)
 	     (type->Tag() != TYPE_VECTOR  || c == INIT_REMOVE) )
 		{
 		if ( c == INIT_EXTRA )
-			Error("+= initializer only applies to tables, sets, vectors and patterns", v);
+			Error("+= initializer only applies to tables, sets, vectors and patterns", v.get());
 		else
-			Error("-= initializer only applies to tables and sets", v);
+			Error("-= initializer only applies to tables and sets", v.get());
 		}
 
 	else
@@ -128,7 +121,7 @@ void ID::SetVal(Val* v, init_class c)
 			{
 			if ( ! val )
 				{
-				SetVal(v);
+				SetVal(std::move(v));
 				return;
 				}
 			else
@@ -140,11 +133,9 @@ void ID::SetVal(Val* v, init_class c)
 				v->RemoveFrom(val);
 			}
 		}
-
-	Unref(v);
 	}
 
-void ID::SetVal(Expr* ev, init_class c)
+void ID::SetVal(IntrusivePtr<Expr> ev, init_class c)
 	{
 	Attr* a = attrs->FindAttr(c == INIT_EXTRA ?
 					ATTR_ADD_FUNC : ATTR_DEL_FUNC);
@@ -152,7 +143,7 @@ void ID::SetVal(Expr* ev, init_class c)
 	if ( ! a )
 		Internal("no add/delete function in ID::SetVal");
 
-	EvalFunc(a->AttrExpr(), ev);
+	EvalFunc({NewRef{}, a->AttrExpr()}, std::move(ev));
 	}
 
 bool ID::IsRedefinable() const
@@ -160,11 +151,10 @@ bool ID::IsRedefinable() const
 	return FindAttr(ATTR_REDEF) != 0;
 	}
 
-void ID::SetAttrs(Attributes* a)
+void ID::SetAttrs(IntrusivePtr<Attributes> a)
 	{
-	Unref(attrs);
 	attrs = 0;
-	AddAttrs(a);
+	AddAttrs(std::move(a));
 	}
 
 void ID::UpdateValAttrs()
@@ -173,10 +163,10 @@ void ID::UpdateValAttrs()
 		return;
 
 	if ( val && val->Type()->Tag() == TYPE_TABLE )
-		val->AsTableVal()->SetAttrs(attrs);
+		val->AsTableVal()->SetAttrs(attrs.get());
 
 	if ( val && val->Type()->Tag() == TYPE_FILE )
-		val->AsFile()->SetAttrs(attrs);
+		val->AsFile()->SetAttrs(attrs.get());
 
 	if ( Type()->Tag() == TYPE_FUNC )
 		{
@@ -222,7 +212,7 @@ void ID::MakeDeprecated(Expr* deprecation)
 		return;
 
 	attr_list* attr = new attr_list{new Attr(ATTR_DEPRECATED, deprecation)};
-	AddAttrs(new Attributes(attr, Type(), false, IsGlobal()));
+	AddAttrs(make_intrusive<Attributes>(attr, Type(), false, IsGlobal()));
 	}
 
 string ID::GetDeprecationWarning() const
@@ -245,12 +235,12 @@ string ID::GetDeprecationWarning() const
 		return fmt("deprecated (%s): %s", Name(), result.c_str());
 	}
 
-void ID::AddAttrs(Attributes* a)
+void ID::AddAttrs(IntrusivePtr<Attributes> a)
 	{
 	if ( attrs )
-		attrs->AddAttrs(a);
+		attrs->AddAttrs(a.release());
 	else
-		attrs = a;
+		attrs = std::move(a);
 
 	UpdateValAttrs();
 	}
@@ -272,20 +262,20 @@ void ID::SetOption()
 	if ( ! IsRedefinable() )
 		{
 		attr_list* attr = new attr_list{new Attr(ATTR_REDEF)};
-		AddAttrs(new Attributes(attr, Type(), false, IsGlobal()));
+		AddAttrs(make_intrusive<Attributes>(attr, Type(), false, IsGlobal()));
 		}
 	}
 
-void ID::EvalFunc(Expr* ef, Expr* ev)
+void ID::EvalFunc(IntrusivePtr<Expr> ef, IntrusivePtr<Expr> ev)
 	{
 	auto arg1 = make_intrusive<ConstExpr>(IntrusivePtr{NewRef{}, val});
 	auto args = make_intrusive<ListExpr>();
 	args->Append(std::move(arg1));
-	args->Append({NewRef{}, ev});
+	args->Append(std::move(ev));
 
-	auto ce = make_intrusive<CallExpr>(IntrusivePtr{NewRef{}, ef}, std::move(args));
+	auto ce = make_intrusive<CallExpr>(std::move(ef), std::move(args));
 
-	SetVal(ce->Eval(0).release());
+	SetVal(ce->Eval(0));
 	}
 
 #if 0
@@ -358,7 +348,7 @@ TraversalCode ID::Traverse(TraversalCallback* cb) const
 void ID::Error(const char* msg, const BroObj* o2)
 	{
 	BroObj::Error(msg, o2, 1);
-	SetType(error_type());
+	SetType({AdoptRef{}, error_type()});
 	}
 
 void ID::Describe(ODesc* d) const
@@ -581,9 +571,9 @@ void ID::UpdateValID()
 	}
 #endif
 
-void ID::AddOptionHandler(Func* callback, int priority)
+void ID::AddOptionHandler(IntrusivePtr<Func> callback, int priority)
 	{
-	option_handlers.insert({priority, callback});
+	option_handlers.emplace(priority, std::move(callback));
 	}
 
 vector<Func*> ID::GetOptionHandlers() const
@@ -593,6 +583,6 @@ vector<Func*> ID::GetOptionHandlers() const
 	// a lot...
 	vector<Func*> v;
 	for ( auto& element : option_handlers )
-		v.push_back(element.second);
+		v.push_back(element.second.get());
 	return v;
 	}
diff --git a/src/ID.h b/src/ID.h
index 0eaf1d42b8..7394bcd450 100644
--- a/src/ID.h
+++ b/src/ID.h
@@ -2,6 +2,7 @@
 
 #pragma once
 
+#include "IntrusivePtr.h"
 #include "Obj.h"
 #include "Attr.h"
 #include "Notifier.h"
@@ -35,9 +36,9 @@ public:
 
 	std::string ModuleName() const;
 
-	void SetType(BroType* t);
-	BroType* Type()			{ return type; }
-	const BroType* Type() const	{ return type; }
+	void SetType(IntrusivePtr<BroType> t);
+	BroType* Type()			{ return type.get(); }
+	const BroType* Type() const	{ return type.get(); }
 
 	void MakeType()			{ is_type = true; }
 	BroType* AsType()		{ return is_type ? Type() : 0; }
@@ -51,10 +52,10 @@ public:
 	// reference to the Val, the Val will be destroyed (naturally,
 	// you have to take care that it will not be accessed via
 	// the ID afterwards).
-	void SetVal(Val* v, bool weak_ref = false);
+	void SetVal(IntrusivePtr<Val> v, bool weak_ref = false);
 
-	void SetVal(Val* v, init_class c);
-	void SetVal(Expr* ev, init_class c);
+	void SetVal(IntrusivePtr<Val> v, init_class c);
+	void SetVal(IntrusivePtr<Expr> ev, init_class c);
 
 	bool HasVal() const		{ return val != 0; }
 	Val* ID_Val()			{ return val; }
@@ -75,11 +76,11 @@ public:
 
 	bool IsRedefinable() const;
 
-	void SetAttrs(Attributes* attr);
-	void AddAttrs(Attributes* attr);
+	void SetAttrs(IntrusivePtr<Attributes> attr);
+	void AddAttrs(IntrusivePtr<Attributes> attr);
 	void RemoveAttr(attr_tag a);
 	void UpdateValAttrs();
-	Attributes* Attrs() const	{ return attrs; }
+	Attributes* Attrs() const	{ return attrs.get(); }
 
 	Attr* FindAttr(attr_tag t) const;
 
@@ -109,11 +110,11 @@ public:
 		{ return !option_handlers.empty(); }
 
 	// Takes ownership of callback.
-	void AddOptionHandler(Func* callback, int priority);
+	void AddOptionHandler(IntrusivePtr<Func> callback, int priority);
 	std::vector<Func*> GetOptionHandlers() const;
 
 protected:
-	void EvalFunc(Expr* ef, Expr* ev);
+	void EvalFunc(IntrusivePtr<Expr> ef, IntrusivePtr<Expr> ev);
 
 #ifdef DEBUG
 	void UpdateValID();
@@ -122,13 +123,13 @@ protected:
 	const char* name;
 	IDScope scope;
 	bool is_export;
-	BroType* type;
+	IntrusivePtr<BroType> type;
 	bool is_const, is_enum_const, is_type, is_option;
 	int offset;
 	Val* val;
-	Attributes* attrs;
+	IntrusivePtr<Attributes> attrs;
 	// contains list of functions that are called when an option changes
-	std::multimap<int, Func*> option_handlers;
+	std::multimap<int, IntrusivePtr<Func>> option_handlers;
 
 	bool infer_return_type;
 	bool weak_ref;
diff --git a/src/Net.cc b/src/Net.cc
index 744bd8a811..6aa3177639 100644
--- a/src/Net.cc
+++ b/src/Net.cc
@@ -194,7 +194,7 @@ void net_init(const std::optional<std::string>& interface,
 					     writefile, pkt_dumper->ErrorMsg());
 
 		if ( ID* id = global_scope()->Lookup("trace_output_file") )
-			id->SetVal(new StringVal(writefile));
+			id->SetVal(make_intrusive<StringVal>(writefile));
 		else
 			reporter->Error("trace_output_file not defined in bro.init");
 		}
diff --git a/src/Type.cc b/src/Type.cc
index 8ab11ce312..cb9bd60bb0 100644
--- a/src/Type.cc
+++ b/src/Type.cc
@@ -1177,7 +1177,7 @@ void EnumType::CheckAndAddName(const string& module_name, const char* name,
 	if ( ! id )
 		{
 		id = install_ID(name, module_name.c_str(), true, is_export);
-		id->SetType(this->Ref());
+		id->SetType({NewRef{}, this});
 		id->SetEnumConst();
 
 		if ( deprecation )
diff --git a/src/Var.cc b/src/Var.cc
index 0399af05cb..80af567595 100644
--- a/src/Var.cc
+++ b/src/Var.cc
@@ -104,15 +104,15 @@ static void make_var(ID* id, IntrusivePtr<BroType> t, init_class c, IntrusivePtr
 		t = {AdoptRef{}, init_type(init.get())};
 		if ( ! t )
 			{
-			id->SetType(error_type());
+			id->SetType({AdoptRef{}, error_type()});
 			return;
 			}
 		}
 
-	id->SetType(t->Ref());
+	id->SetType(t);
 
 	if ( attr )
-		id->AddAttrs(new Attributes(attr, t.get(), false, id->IsGlobal()));
+		id->AddAttrs(make_intrusive<Attributes>(attr, t.get(), false, id->IsGlobal()));
 
 	if ( init )
 		{
@@ -121,10 +121,7 @@ static void make_var(ID* id, IntrusivePtr<BroType> t, init_class c, IntrusivePtr
 			{
 			TableConstructorExpr* ctor = (TableConstructorExpr*) init.get();
 			if ( ctor->Attrs() )
-				{
-				::Ref(ctor->Attrs());
-				id->AddAttrs(ctor->Attrs());
-				}
+				id->AddAttrs({NewRef{}, ctor->Attrs()});
 			}
 			break;
 
@@ -132,10 +129,7 @@ static void make_var(ID* id, IntrusivePtr<BroType> t, init_class c, IntrusivePtr
 			{
 			SetConstructorExpr* ctor = (SetConstructorExpr*) init.get();
 			if ( ctor->Attrs() )
-				{
-				::Ref(ctor->Attrs());
-				id->AddAttrs(ctor->Attrs());
-				}
+				id->AddAttrs({NewRef{}, ctor->Attrs()});
 			}
 			break;
 
@@ -155,7 +149,7 @@ static void make_var(ID* id, IntrusivePtr<BroType> t, init_class c, IntrusivePtr
 		if ( init && ((c == INIT_EXTRA && id->FindAttr(ATTR_ADD_FUNC)) ||
 		              (c == INIT_REMOVE && id->FindAttr(ATTR_DEL_FUNC)) ))
 			// Just apply the function.
-			id->SetVal(init->Ref(), c);
+			id->SetVal(init, c);
 
 		else if ( dt != VAR_REDEF || init || ! attr )
 			{
@@ -184,9 +178,9 @@ static void make_var(ID* id, IntrusivePtr<BroType> t, init_class c, IntrusivePtr
 				}
 
 			if ( aggr )
-				id->SetVal(aggr.release(), c);
+				id->SetVal(std::move(aggr), c);
 			else if ( v )
-				id->SetVal(v.release(), c);
+				id->SetVal(std::move(v), c);
 			}
 		}
 
@@ -216,7 +210,7 @@ static void make_var(ID* id, IntrusivePtr<BroType> t, init_class c, IntrusivePtr
 		// we can later access the ID even if no implementations have been
 		// defined.
 		Func* f = new BroFunc(id, 0, 0, 0, 0);
-		id->SetVal(new Val(f));
+		id->SetVal(make_intrusive<Val>(f));
 		}
 	}
 
@@ -284,11 +278,11 @@ void add_type(ID* id, IntrusivePtr<BroType> t, attr_list* attr)
 
 	tnew->SetName(id->Name());
 
-	id->SetType(IntrusivePtr{tnew}.release());
+	id->SetType(tnew);
 	id->MakeType();
 
 	if ( attr )
-		id->SetAttrs(new Attributes(attr, tnew.get(), false, false));
+		id->SetAttrs(make_intrusive<Attributes>(attr, tnew.get(), false, false));
 	}
 
 static void transfer_arg_defaults(RecordType* args, RecordType* recv)
@@ -386,7 +380,7 @@ void begin_func(ID* id, const char* module_name, function_flavor flavor,
 		}
 		}
 	else
-		id->SetType(IntrusivePtr{t}.release());
+		id->SetType(t);
 
 	push_scope(id, attrs);
 
@@ -402,7 +396,7 @@ void begin_func(ID* id, const char* module_name, function_flavor flavor,
 			arg_id->Error("argument name used twice");
 
 		arg_id = install_ID(arg_i->id, module_name, false, false);
-		arg_id->SetType(arg_i->type->Ref());
+		arg_id->SetType({NewRef{}, arg_i->type});
 		}
 
 	if ( Attr* depr_attr = find_attr(attrs, ATTR_DEPRECATED) )
@@ -494,7 +488,7 @@ void end_func(IntrusivePtr<Stmt> body)
 			ingredients->frame_size,
 			ingredients->priority);
 
-		ingredients->id->SetVal(new Val(f));
+		ingredients->id->SetVal(make_intrusive<Val>(f));
 		ingredients->id->SetConst();
 		}
 
diff --git a/src/broker/Manager.cc b/src/broker/Manager.cc
index e71612597d..0a24a5ebc4 100644
--- a/src/broker/Manager.cc
+++ b/src/broker/Manager.cc
@@ -1210,7 +1210,7 @@ bool Manager::ProcessIdentifierUpdate(broker::zeek::IdentifierUpdate iu)
 		return false;
 		}
 
-	id->SetVal(val.release());
+	id->SetVal(std::move(val));
 	return true;
 	}
 
diff --git a/src/main.cc b/src/main.cc
index b47d2fcf59..30334c5b3e 100644
--- a/src/main.cc
+++ b/src/main.cc
@@ -717,7 +717,7 @@ int main(int argc, char** argv)
 		if ( ! id )
 			reporter->InternalError("global cmd_line_bpf_filter not defined");
 
-		id->SetVal(new StringVal(*options.pcap_filter));
+		id->SetVal(make_intrusive<StringVal>(*options.pcap_filter));
 		}
 
 	auto all_signature_files = options.signature_files;
diff --git a/src/option.bif b/src/option.bif
index 8c56fe4c38..5355216ee7 100644
--- a/src/option.bif
+++ b/src/option.bif
@@ -33,7 +33,7 @@ static bool call_option_handlers_and_set_value(StringVal* name, ID* i, Val* val,
 		}
 
 	// clone to prevent changes
-	i->SetVal(val->Clone());
+	i->SetVal({AdoptRef{}, val->Clone()});
 	Unref(val); // Either ref'd once or function call result.
 	return true;
 	}
@@ -206,7 +206,6 @@ function Option::set_change_handler%(ID: string, on_change: any, priority: int &
 		}
 
 	auto* func = on_change->AsFunc();
-	Ref(func);
-	i->AddOptionHandler(func, -priority);
+	i->AddOptionHandler({NewRef{}, func}, -priority);
 	return val_mgr->GetBool(1);
 	%}
diff --git a/src/parse.y b/src/parse.y
index 3f9c51e973..c11242e7ec 100644
--- a/src/parse.y
+++ b/src/parse.y
@@ -693,7 +693,7 @@ expr:
 				if ( ! id->Type() )
 					{
 					id->Error("undeclared variable");
-					id->SetType(error_type());
+					id->SetType({AdoptRef{}, error_type()});
 					$$ = new NameExpr(std::move(id));
 					}
 
@@ -1623,7 +1623,7 @@ case_type:
 		TOK_TYPE type
 			{
 			$$ = new ID(0, SCOPE_FUNCTION, 0);
-			$$->SetType($2);
+			$$->SetType({AdoptRef{}, $2});
 			}
 
 	|	TOK_TYPE type TOK_AS TOK_ID
diff --git a/src/supervisor/Supervisor.cc b/src/supervisor/Supervisor.cc
index 097724665b..3d91725b26 100644
--- a/src/supervisor/Supervisor.cc
+++ b/src/supervisor/Supervisor.cc
@@ -1233,7 +1233,7 @@ bool Supervisor::SupervisedNode::InitCluster() const
 		cluster_nodes->Assign(key.get(), val.release());
 		}
 
-	cluster_manager_is_logger_id->SetVal(val_mgr->GetBool(! has_logger));
+	cluster_manager_is_logger_id->SetVal({AdoptRef{}, val_mgr->GetBool(! has_logger)});
 	return true;
 	}