diff --git a/composer.json b/composer.json
index b594bc3..dd17cc9 100644
--- a/composer.json
+++ b/composer.json
@@ -10,7 +10,7 @@
         }
     ],
     "require": {
-        "mcnd/ulmus": "dev-master"
+        "mcnd/ulmus": "^1.0 || ^2.0"
     },
     "repositories": [
         {