diff --git a/ext/gd/gd.c b/ext/gd/gd.c
index cdec117ea6b..ef9e3cdd0fc 100644
--- a/ext/gd/gd.c
+++ b/ext/gd/gd.c
@@ -1729,7 +1729,7 @@ PHP_FUNCTION(imagecolorallocatealpha)
 	gdImagePtr im;
 	int ct = (-1);
 
-	if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "zllll", &IM, &red, &green, &blue, &alpha) == FAILURE) {
+	if (zend_parse_parameters(ZEND_NUM_ARGS() TSRMLS_CC, "rllll", &IM, &red, &green, &blue, &alpha) == FAILURE) {
 		RETURN_FALSE;
 	}