diff --git a/source/blender/python/intern/bpy_props.c b/source/blender/python/intern/bpy_props.c
index bd033736865..57ddee0c8c0 100644
--- a/source/blender/python/intern/bpy_props.c
+++ b/source/blender/python/intern/bpy_props.c
@@ -1233,6 +1233,8 @@ BPY_PROPDEF_DESC_DOC
 "      For dynamic values a callback can be passed which returns a list in\n"
 "      the same format as the static list.\n"
 "      This function must take 2 arguments (self, context)\n"
+"      WARNING: Do not use generators here (they will work the first time, but will lead to empty values\n"
+"               in some unload/reload scenarii)!\n"
 "   :type items: sequence of string triplets or a function\n"
 BPY_PROPDEF_UPDATE_DOC
 );