--- a/cmajor++/Cm/Cm.Core/Error.hpp
+++ b/cmajor++/Cm/Cm.Core/Error.hpp
@@ -236,6 +236,7 @@
 const int SYSTEM_EXCEPTION_HAS_NO_TYPE = 158;
 const int EXCEPTIONS_MUST_BE_DERIVED_FROM_SYSTEM_EXCEPTION_CLASS = 159;
 const int ARGUMENT_HAS_CANNOT_BE_A_FUNCTIONSET = 160;
+const int DELEGATE_MUST_HAVE_RETURN_TYPE = 161;
 
 // Code generation errors:
 const int PROGRAM_DOES_NOT_CONTAIN_MAIN = 1;