diff --git a/hemlock/group.lisp b/hemlock/group.lisp
index e962d5259ec31eb03408c4a8b0f39fb0f447b118..8c5eedbb12315dbac46a8eb86cb8ef437b3410cd 100644
--- a/hemlock/group.lisp
+++ b/hemlock/group.lisp
@@ -78,7 +78,7 @@
     (do* ((name (read-line file nil nil) (read-line file nil nil))
 	  (length (if name (length name)) (if name (length name))))
 	 ((null name) tail)
-      (declare (simple-string name))
+      (declare (type (or simple-string null) name))
       (cond ((zerop length))
 	    ((char= (char name 0) #\@)
 	     (when (and (> length 1) (char= (char name 1) #\@))