1 files changed, 3 insertions, 7 deletions

diff --git a/lisp/isearch.el b/lisp/isearch.el
index 1057547cb3f..118d23ce38f 100644
--- a/lisp/isearch.el
+++ b/lisp/isearch.el
@@ -1682,13 +1682,9 @@ Isearch mode."
     ;; single-byte character set, and convert them to Emacs
     ;; characters.
     (if (and isearch-regexp (= char ?\ ))
-        (if (condition-case err
-                (progn
-                  (string-match isearch-string "")
-                  nil)
-              (error (equal (cadr err) "Unmatched [ or [^")))
-            (isearch-process-search-char char)
-          (isearch-process-search-string "[ ]" " "))
+        (if (subregexp-context-p isearch-string pos)
+            (isearch-process-search-string "[ ]" " ")
+          (isearch-process-search-char char))
       (and enable-multibyte-characters
            (>= char ?\200)
            (<= char ?\377)