1 files changed, 1 insertions, 1 deletions
diff --git a/composer.json b/composer.json
index 238b8cf..7d3a225 100644
--- a/composer.json
+++ b/composer.json
@@ -23,6 +23,6 @@
         "ext-xml": "*"
     },
     "require-dev": {
-        "phpunit/phpunit": "4.*"
+        "phpunit/phpunit": "^5.7"
     }
 }