diff --git a/ac-slime.el b/ac-slime.el
index cd1c18c..a2efd3f 100644
--- a/ac-slime.el
+++ b/ac-slime.el
@@ -21,7 +21,8 @@
 (require 'slime)
 (require 'auto-complete)
 
-(defgroup ac-slime
+(defgroup ac-slime nil
+  "Slime auto-complete customizations"
   :prefix "ac-slime-"
   :group 'slime)