diff --git a/Auxiliary/cmake-mode.el b/Auxiliary/cmake-mode.el
index e50ae7b95..08ac4905e 100644
--- a/Auxiliary/cmake-mode.el
+++ b/Auxiliary/cmake-mode.el
@@ -177,7 +177,7 @@ the indentation.  Otherwise it retains the same position on the line"
   (interactive)
   (save-excursion
     (goto-char (point-min))
-    (while (re-search-forward "^\\([ \t]*\\)\\(\\w+\\)\\([ \t]*(\\)" nil t)
+    (while (re-search-forward "^\\([ \t]*\\)\\_<\\(\\(?:\\w\\|\\s_\\)+\\)\\_>\\([ \t]*(\\)" nil t)
       (replace-match
        (concat
         (match-string 1)