diff --git a/.gitignore b/.gitignore
index 8c126ea..702af8e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,3 @@
+composer.lock
 vendor/
 .DS_Store
diff --git a/composer.json b/composer.json
index 773ed0c..5210821 100644
--- a/composer.json
+++ b/composer.json
@@ -14,7 +14,7 @@
     "php": ">=5.5"
   },
   "require-dev": {
-    "phpunit/phpunit": ">=4.8.13"
+    "phpunit/phpunit": "^4.8.13"
   },
   "autoload": {
     "files": [