diff --git a/composer.json b/composer.json
index d241f55..d7b5ebe 100644
--- a/composer.json
+++ b/composer.json
@@ -23,7 +23,7 @@
     "require": {
         "php": "^7.2|^8.0",
         "neomerx/cors-psr7": "^2.0|^3.0",
-        "psr/http-message": "^1.0.1",
+        "psr/http-message": "^1.0.1|^2.0",
         "psr/http-server-middleware": "^1.0",
         "tuupola/callable-handler": "^1.0",
         "tuupola/http-factory": "^1.0.2"