--- a/cmajor++/Cm/Cm.Core/Util.cpp
+++ b/cmajor++/Cm/Cm.Core/Util.cpp
@@ -67,7 +67,7 @@
 
 FactoryPtr Factory::Instance()
 {
-    CM_CORE_ASSERT(instance);
+    CM_CORE_ASSERT(instance, nullptr);
     return instance;
 }
 
@@ -379,7 +379,7 @@
 
 MangleMapPtr MangleMap::Instance()
 {
-    CM_CORE_ASSERT(instance);
+    CM_CORE_ASSERT(instance, nullptr);
     return instance;
 }