diff --git a/source/scriptinterface/ScriptInterface.cpp b/source/scriptinterface/ScriptInterface.cpp
index 63e633756a..0f6297ffd9 100644
--- a/source/scriptinterface/ScriptInterface.cpp
+++ b/source/scriptinterface/ScriptInterface.cpp
@@ -1135,16 +1135,18 @@ bool ScriptInterface::SetPrototype(JS::HandleValue obj, JS::HandleValue proto)
 	return JS_SetPrototype(m->m_cx, &obj.toObject(), &proto.toObject());
 }
 
-bool ScriptInterface::FreezeObject(jsval obj, bool deep)
+bool ScriptInterface::FreezeObject(JS::HandleValue objVal, bool deep)
 {
 	JSAutoRequest rq(m->m_cx);
-	if (!obj.isObject())
+	if (!objVal.isObject())
 		return false;
+	
+	JS::RootedObject obj(m->m_cx, &objVal.toObject());
 
 	if (deep)
-		return JS_DeepFreezeObject(m->m_cx, &obj.toObject());
+		return JS_DeepFreezeObject(m->m_cx, obj);
 	else
-		return JS_FreezeObject(m->m_cx, &obj.toObject());
+		return JS_FreezeObject(m->m_cx, obj);
 }
 
 bool ScriptInterface::LoadScript(const VfsPath& filename, const std::string& code)
diff --git a/source/scriptinterface/ScriptInterface.h b/source/scriptinterface/ScriptInterface.h
index 19fa57ea67..31253bf4ae 100644
--- a/source/scriptinterface/ScriptInterface.h
+++ b/source/scriptinterface/ScriptInterface.h
@@ -258,7 +258,7 @@ public:
 
 	bool SetPrototype(JS::HandleValue obj, JS::HandleValue proto);
 
-	bool FreezeObject(jsval obj, bool deep);
+	bool FreezeObject(JS::HandleValue objVal, bool deep);
 
 	bool Eval(const char* code);
 
diff --git a/source/simulation2/components/CCmpAIManager.cpp b/source/simulation2/components/CCmpAIManager.cpp
index 25353daae6..980730c718 100644
--- a/source/simulation2/components/CCmpAIManager.cpp
+++ b/source/simulation2/components/CCmpAIManager.cpp
@@ -572,7 +572,7 @@ public:
 		// Since the template data is shared between AI players, freeze it
 		// to stop any of them changing it and confusing the other players
 		m_EntityTemplates = CScriptValRooted(cx, tmpEntityTemplates);
-		m_ScriptInterface->FreezeObject(m_EntityTemplates.get(), true);
+		m_ScriptInterface->FreezeObject(tmpEntityTemplates, true);
 	}
 
 	void Serialize(std::ostream& stream, bool isDebug)