diff --git a/config.m4 b/config.m4
index 9002b5d..ddaa2b1 100644
--- a/config.m4
+++ b/config.m4
@@ -6,10 +6,10 @@ PHP_ARG_ENABLE(collections, for debug support,
 
 if test "$PHP_COLLECTIONS" != "no"; then
   if test "$PHP_COLLECTIONS_DEBUG" != "no"; then
-    EXTRA_CFLAGS="-O2"
+    CFLAGS="-O2"
   else
-    EXTRA_CFLAGS="-g -O0"
+    CFLAGS="-g -O0"
   fi
   COLLECTIONS_SRC="collections.c collections_fe.c collections_methods.c"
-  PHP_NEW_EXTENSION(collections, $COLLECTIONS_SRC, $ext_shared,, $EXTRA_CFLAGS)
+  PHP_NEW_EXTENSION(collections, $COLLECTIONS_SRC, $ext_shared)
 fi