diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index 7f43a3634d9..f1aa40ccc9a 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,8 @@
+2013-05-08  Tom Tromey  <tromey@redhat.com>
+
+	* progmodes/m4-mode.el (m4-mode-syntax-table):
+	Do not treat "_" as word constituent.  (Bug#14167)
+
 2013-05-07  Glenn Morris  <rgm@gnu.org>
 
 	* eshell/em-hist.el (eshell-isearch-map): Initialize in the defvar.
diff --git a/lisp/progmodes/m4-mode.el b/lisp/progmodes/m4-mode.el
index 0641fc776de..ffd79b354d5 100644
--- a/lisp/progmodes/m4-mode.el
+++ b/lisp/progmodes/m4-mode.el
@@ -95,7 +95,7 @@
 (modify-syntax-entry ?{  "_" m4-mode-syntax-table)
 (modify-syntax-entry ?}  "_" m4-mode-syntax-table)
 (modify-syntax-entry ?*  "w" m4-mode-syntax-table)
-(modify-syntax-entry ?_  "w" m4-mode-syntax-table)
+(modify-syntax-entry ?_  "_" m4-mode-syntax-table)
 (modify-syntax-entry ?\"  "w" m4-mode-syntax-table)
 (modify-syntax-entry ?\"  "w" m4-mode-syntax-table)