diff --git a/.changes/nextrelease/http-message-fix.json b/.changes/nextrelease/http-message-fix.json
new file mode 100644
index 0000000000..4629d84ef6
--- /dev/null
+++ b/.changes/nextrelease/http-message-fix.json
@@ -0,0 +1,7 @@
+[
+  {
+    "type": "enhancement",
+    "category": "",
+    "description": "Takes explicit dependency on psr/http-message >= 1.0 to avoid conflicts."
+  }
+]
\ No newline at end of file
diff --git a/composer.json b/composer.json
index 0fbde38895..e96eaff9fc 100644
--- a/composer.json
+++ b/composer.json
@@ -24,7 +24,8 @@
         "ext-pcre": "*",
         "ext-json": "*",
         "ext-simplexml": "*",
-        "aws/aws-crt-php": "^1.0.4"
+        "aws/aws-crt-php": "^1.0.4",
+        "psr/http-message": "^1.0"
     },
     "require-dev": {
         "composer/composer" : "^1.10.22",
@@ -39,7 +40,6 @@
         "nette/neon": "^2.3",
         "andrewsville/php-token-reflection": "^1.4",
         "psr/cache": "^1.0",
-        "psr/http-message": "^1.0",
         "psr/simple-cache": "^1.0",
         "paragonie/random_compat": ">= 2",
         "sebastian/comparator": "^1.2.3 || ^4.0",