diff --git a/lisp/gnus/gnus-search.el b/lisp/gnus/gnus-search.el
index fc9f8684f6..71a65ab95d 100644
--- a/lisp/gnus/gnus-search.el
+++ b/lisp/gnus/gnus-search.el
@@ -1347,15 +1347,18 @@ gnus-search-indexed-parse-output
 						server query &optional groups)
   (let ((prefix (slot-value engine 'remove-prefix))
 	(group-regexp (when groups
-			(mapconcat
-			 (lambda (group-name)
-			   (mapconcat #'regexp-quote
-				      (split-string
-				       (gnus-group-real-name group-name)
-				       "[.\\/]")
-				      "[.\\\\/]"))
-			 groups
-			 "\\|")))
+                        (concat
+                         "\\`"
+			 (mapconcat
+			  (lambda (group-name)
+			    (mapconcat #'regexp-quote
+				       (split-string
+				        (gnus-group-real-name group-name)
+				        "[.\\/]")
+				       "[.\\\\/]"))
+			  groups
+			  "\\|")
+                         "\\'")))
 	artlist vectors article group)
     (goto-char (point-min))
     (while (not (or (eobp)