diff --git a/src/Defines.hpp b/src/Defines.hpp
index 6dcece9..9832962 100644
--- a/src/Defines.hpp
+++ b/src/Defines.hpp
@@ -11,6 +11,8 @@ typedef uint16_t level_int_t;
 typedef uint32_t level_int_t;
 #elif LEVEL_U64
 typedef uint64_t level_int_t;
+#else
+#error No Level size was specified
 #endif
 
 #endif // CREATURELIB_DEFINES_HPP