diff --git a/build/php.m4 b/build/php.m4
index f94c28c2452d3..40db6023136b9 100644
--- a/build/php.m4
+++ b/build/php.m4
@@ -2029,8 +2029,8 @@ EOF
   echo '"[$]@"' >> $1
   chmod +x $1
   CONFIGURE_COMMAND="$CONFIGURE_COMMAND $CONFIGURE_OPTIONS"
-  PHP_SUBST_OLD(CONFIGURE_COMMAND)
-  PHP_SUBST_OLD(CONFIGURE_OPTIONS)
+  AC_SUBST([CONFIGURE_COMMAND])
+  AC_SUBST([CONFIGURE_OPTIONS])
 ])
 
 dnl