diff --git a/aclocal.m4 b/aclocal.m4
index 0811dfda..bb528c71 100644
--- a/aclocal.m4
+++ b/aclocal.m4
@@ -5923,7 +5923,7 @@ AC_MSG_RESULT([$SED])
 dnl PKG_CHECK_MODULES(GSTUFF, gtk+-2.0 >= 1.3 glib = 1.3.4, action-if, action-not)
 dnl defines GSTUFF_LIBS, GSTUFF_CFLAGS, see pkg-config man page
 dnl also defines GSTUFF_PKG_ERRORS on error
-AC_DEFUN(PKG_CHECK_MODULES, [
+AC_DEFUN([PKG_CHECK_MODULES], [
   succeeded=no
 
   if test -z "$PKG_CONFIG"; then