diff --git a/src/parse.y b/src/parse.y
index 3f79e4331c..f2337ec653 100644
--- a/src/parse.y
+++ b/src/parse.y
@@ -1119,7 +1119,7 @@ decl:
 			IntrusivePtr id{AdoptRef{}, $2};
 			IntrusivePtr<Expr> init{AdoptRef{}, $5};
 			add_global(id.get(), {AdoptRef{}, $3}, $4, init, $6, VAR_REDEF);
-			zeekygen_mgr->Redef(id.get(), ::filename, $4, init.release());
+			zeekygen_mgr->Redef(id.get(), ::filename, $4, std::move(init));
 			}
 
 	|	TOK_REDEF TOK_ENUM global_id TOK_ADD_TO '{'
diff --git a/src/zeekygen/IdentifierInfo.cc b/src/zeekygen/IdentifierInfo.cc
index 49ae1ad856..5727e3860c 100644
--- a/src/zeekygen/IdentifierInfo.cc
+++ b/src/zeekygen/IdentifierInfo.cc
@@ -32,9 +32,9 @@ IdentifierInfo::~IdentifierInfo()
 	}
 
 void IdentifierInfo::AddRedef(const string& script, init_class ic,
-                              Expr* init_expr, const vector<string>& comments)
+                              IntrusivePtr<Expr> init_expr, const vector<string>& comments)
 	{
-	Redefinition* redef = new Redefinition(script, ic, init_expr, comments);
+	Redefinition* redef = new Redefinition(script, ic, std::move(init_expr), comments);
 	redefs.push_back(redef);
 	}
 
@@ -142,49 +142,16 @@ time_t IdentifierInfo::DoGetModificationTime() const
 IdentifierInfo::Redefinition::Redefinition(
                        std::string arg_script,
                        init_class arg_ic,
-                       Expr* arg_expr,
+                       IntrusivePtr<Expr> arg_expr,
                        std::vector<std::string> arg_comments)
 			: from_script(std::move(arg_script)),
 			  ic(arg_ic),
-			  init_expr(arg_expr ? arg_expr->Ref() : nullptr),
+			  init_expr(std::move(arg_expr)),
 			  comments(std::move(arg_comments))
 	{
 	}
 
-IdentifierInfo::Redefinition::Redefinition(const IdentifierInfo::Redefinition& other)
-	{
-	from_script = other.from_script;
-	ic = other.ic;
-	init_expr = other.init_expr;
-	comments = other.comments;
-
-	if ( init_expr )
-		init_expr->Ref();
-	}
-
-IdentifierInfo::Redefinition&
-IdentifierInfo::Redefinition::operator=(const IdentifierInfo::Redefinition& other)
-	{
-	if ( &other == this )
-		return *this;
-
-	Unref(init_expr);
-
-	from_script = other.from_script;
-	ic = other.ic;
-	init_expr = other.init_expr;
-	comments = other.comments;
-
-	if ( init_expr )
-		init_expr->Ref();
-
-	return *this;
-	}
-
-IdentifierInfo::Redefinition::~Redefinition()
-	{
-	Unref(init_expr);
-	}
+IdentifierInfo::Redefinition::~Redefinition() = default;
 
 IdentifierInfo::RecordField::~RecordField()
 	{
diff --git a/src/zeekygen/IdentifierInfo.h b/src/zeekygen/IdentifierInfo.h
index 947378d1f0..949a503664 100644
--- a/src/zeekygen/IdentifierInfo.h
+++ b/src/zeekygen/IdentifierInfo.h
@@ -71,7 +71,7 @@ public:
 	 * @param comments Comments associated with the redef statement.
 	 */
 	void AddRedef(const std::string& from_script, init_class ic,
-	              Expr* init_expr,
+	              IntrusivePtr<Expr> init_expr,
 	              const std::vector<std::string>& comments);
 
 	/**
@@ -128,17 +128,13 @@ public:
 	struct Redefinition {
 		std::string from_script; /**< Name of script doing the redef. */
 		init_class ic;
-		Expr* init_expr;
+		IntrusivePtr<Expr> init_expr;
 		std::vector<std::string> comments; /**< Zeekygen comments on redef. */
 
 		Redefinition(std::string arg_script, init_class arg_ic,
-	                 Expr* arg_expr,
+		             IntrusivePtr<Expr> arg_expr,
 		             std::vector<std::string> arg_comments);
 
-		Redefinition(const Redefinition& other);
-
-		Redefinition& operator=(const Redefinition& other);
-
 		~Redefinition();
 	};
 
diff --git a/src/zeekygen/Manager.cc b/src/zeekygen/Manager.cc
index f9e4e48585..b61cb15404 100644
--- a/src/zeekygen/Manager.cc
+++ b/src/zeekygen/Manager.cc
@@ -7,6 +7,7 @@
 #include "PackageInfo.h"
 #include "ScriptInfo.h"
 #include "IdentifierInfo.h"
+#include "Expr.h"
 
 #include <utility>
 #include <cstdlib>
@@ -359,7 +360,7 @@ void Manager::RecordField(const ID* id, const TypeDecl* field,
 	}
 
 void Manager::Redef(const ID* id, const string& path,
-                    init_class ic, Expr* init_expr)
+                    init_class ic, IntrusivePtr<Expr> init_expr)
 	{
 	if ( disabled )
 		return;
@@ -387,7 +388,7 @@ void Manager::Redef(const ID* id, const string& path,
 		return;
 		}
 
-	id_info->AddRedef(from_script, ic, init_expr, comment_buffer);
+	id_info->AddRedef(from_script, ic, std::move(init_expr), comment_buffer);
 	script_info->AddRedef(id_info);
 	comment_buffer.clear();
 	last_identifier_seen = id_info;
@@ -395,6 +396,12 @@ void Manager::Redef(const ID* id, const string& path,
 	        id->Name(), from_script.c_str());
 	}
 
+void Manager::Redef(const ID* id, const std::string& path,
+                    init_class ic)
+	{
+	Redef(id, path, ic, nullptr);
+	}
+
 void Manager::SummaryComment(const string& script, const string& comment)
 	{
 	if ( disabled )
diff --git a/src/zeekygen/Manager.h b/src/zeekygen/Manager.h
index a22dada278..aca2f07c5c 100644
--- a/src/zeekygen/Manager.h
+++ b/src/zeekygen/Manager.h
@@ -14,6 +14,7 @@
 #include <sys/stat.h>
 #include <errno.h>
 
+template <class T> class IntrusivePtr;
 class TypeDecl;
 
 namespace zeekygen {
@@ -138,7 +139,9 @@ public:
 	 * @param init_expr The intiialization expression that was used.
 	 */
 	void Redef(const ID* id, const std::string& path,
-			   init_class ic = INIT_NONE, Expr* init_expr = nullptr);
+			   init_class ic, IntrusivePtr<Expr> init_expr);
+	void Redef(const ID* id, const std::string& path,
+			   init_class ic = INIT_NONE);
 
 	/**
 	 * Register Zeekygen script summary content.