diff --git a/ext/interbase/ibase_query.c b/ext/interbase/ibase_query.c
index b6c4709092c..e5b8131a50c 100644
--- a/ext/interbase/ibase_query.c
+++ b/ext/interbase/ibase_query.c
@@ -1212,7 +1212,7 @@ PHP_FUNCTION(ibase_affected_rows)
 {
 	ibase_trans *trans = NULL;
 	ibase_db_link *ib_link;
-	zval *arg;
+	zval *arg = NULL;
 		
 	RESET_ERRMSG;
 	
@@ -1220,7 +1220,7 @@ PHP_FUNCTION(ibase_affected_rows)
 		return;
 	}
 
-	if (ZEND_NUM_ARGS() == 0) {
+	if (!arg) {
 		ZEND_FETCH_RESOURCE2(ib_link, ibase_db_link *, NULL, IBG(default_link), LE_LINK, le_link, le_plink);
 		if (ib_link->tr_list == NULL || ib_link->tr_list->trans == NULL) {
 			RETURN_FALSE;