diff --git a/direct/src/showbase/ShowBaseGlobal.py b/direct/src/showbase/ShowBaseGlobal.py
index 4a4ca05085..b4f0b510b5 100644
--- a/direct/src/showbase/ShowBaseGlobal.py
+++ b/direct/src/showbase/ShowBaseGlobal.py
@@ -14,3 +14,7 @@ def inspect(anObject):
 
 __builtins__["inspect"] = inspect
 __builtins__["__dev__"] = base.config.GetBool('want-dev', 0)
+# this also appears in AIBaseGlobal
+if (not __debug__) and __dev__:
+    notify = directNotify.newCategory('ShowBaseGlobal')
+    notify.error("You must set 'want-dev' to false in non-debug mode.")