diff --git a/m4/search-libs.m4 b/m4/search-libs.m4
index 6979ea8e5..1d0cf6e6f 100644
--- a/m4/search-libs.m4
+++ b/m4/search-libs.m4
@@ -1,4 +1,4 @@
-#serial 1
+#serial 2
 
 dnl A replacement for autoconf's macro by the same name.  This version
 dnl uses `ac_lib' rather than `i' for the loop variable, but more importantly
@@ -6,7 +6,7 @@ dnl moves the ACTION-IF-FOUND ($3) into the inner `if'-block so that it is
 dnl run only if one of the listed libraries ends up being used (and not in
 dnl the `none required' case.
 dnl I hope it's only temporary while we wait for that version to be fixed.
-undefine(AC_SEARCH_LIBS)
+undefine([AC_SEARCH_LIBS])
 
 dnl AC_SEARCH_LIBS(FUNCTION, SEARCH-LIBS [, ACTION-IF-FOUND
 dnl            [, ACTION-IF-NOT-FOUND [, OTHER-LIBRARIES]]])
@@ -31,12 +31,12 @@ AC_DEFUN(AC_SEARCH_LIBS,
     LIBS="$ac_func_search_save_LIBS"
   ])
 
-  if test "$ac_cv_search_$1" = "no"; then
+  if test "$ac_cv_search_$1" = "no"; then :
     $4
   else
-    if test "$ac_cv_search_$1" = "none required"; then
+    if test "$ac_cv_search_$1" = "none required"; then :
       $4
-    else :
+    else
       LIBS="$ac_cv_search_$1 $LIBS"
       $3
     fi