diff --git a/composer.json b/composer.json
index de8df87..49b77b3 100644
--- a/composer.json
+++ b/composer.json
@@ -24,7 +24,7 @@
     },
     "require": {
         "php": ">=5.4.0",
-        "portphp/portphp": "1.0.x-dev"
+        "portphp/portphp": "^1.0.0"
     },
     "autoload": {
         "psr-4": {
@@ -42,7 +42,7 @@
     },
     "extra": {
         "branch-alias": {
-            "dev-master": "1.0.x-dev"
+            "dev-master": "2.0.x-dev"
         }
     }
 }