diff --git a/src/cpu/core_normal.cpp b/src/cpu/core_normal.cpp
index 73522a22..c7c77f73 100644
--- a/src/cpu/core_normal.cpp
+++ b/src/cpu/core_normal.cpp
@@ -181,7 +181,11 @@ restart_opcode:
 		#include "core_normal/prefix_66_0f.h"
 		default:
 			ADDIPFAST(-1);
+#if C_DEBUG
 			LOG_MSG("Unhandled code %X",core.opcode_index+Fetchb());
+#else
+			E_Exit("Unhandled CPU opcode");
+#endif
 		}
 	}
 	decode_end: