diff --git a/composer.json b/composer.json
index 8637c6d..99ce60a 100644
--- a/composer.json
+++ b/composer.json
@@ -25,7 +25,7 @@
         "mikey179/vfsStream": "^1.6"
     },
     "provide": {
-        " psr/http-message-implementation": "1.0"
+        "psr/http-message-implementation": "~1.0.0"
     },
     "autoload": {
         "psr-4": {