--- a/cmajor++/Cm/Cm.Core/Library.cpp
+++ b/cmajor++/Cm/Cm.Core/Library.cpp
@@ -145,7 +145,7 @@
 
 void Library::ParseTemplateCompilationUnit(int templateSourceFileIndex)
 {
-    CM_CORE_ASSERT(templateSourceFileParser);
+    CM_CORE_ASSERT(templateSourceFileParser, nullptr);
     if (templateSourceFileIndex < 0 || templateSourceFileIndex >= sourceFilePaths.size())
     {
         throw std::runtime_error("invalid template source file path index");