diff --git a/composer.json b/composer.json
index fa2be97..bf59c3b 100644
--- a/composer.json
+++ b/composer.json
@@ -21,7 +21,7 @@
     },
     "require": {
         "php": ">=5.5.0",
-        "99designs/http-signatures": ">=3.0.0 <4.0.0",
+        "99designs/http-signatures": ">=3.0.0 <5.0.0",
         "guzzlehttp/guzzle": ">=6.0 <7.0.0"
     },
     "require-dev": {