diff --git a/composer.json b/composer.json
index 579b35a..abe0f64 100644
--- a/composer.json
+++ b/composer.json
@@ -40,7 +40,7 @@
     "php-http/promise": "1.1.* || 1.0.*",
     "psr/http-client": "1.0.*",
     "psr/http-factory": "1.0.*",
-    "psr/http-message": "1.0.*",
+    "psr/http-message": "1.1",
     "psr/log": "1.1.*",
     "voku/portable-utf8": "~6.0",
     "voku/simple_html_dom": "~4.7"