diff --git a/composer.json b/composer.json
index 55b5a49c55bf926b0467b57a6b5b6df442a92b67..4906abb508a0ab54d13b817bc2b99e1f1fb967b9 100644
--- a/composer.json
+++ b/composer.json
@@ -16,7 +16,6 @@
     "autoload": {
         "psr-4": {
             "Tal\\": "src"
-        },
-        "files": ["src/functions.php"]
+        }
     }
 }
diff --git a/src/MessageTrait.php b/src/MessageTrait.php
index 041dbb4aa6d0c34311abf7d047fd7af86f358b18..513154b8d92e51cab543898bdf82bf4e5f74a072 100644
--- a/src/MessageTrait.php
+++ b/src/MessageTrait.php
@@ -237,10 +237,6 @@ trait MessageTrait
     {
         $normalized = strtolower($header);
 
-        if (!isset($this->headerNames[$normalized])) {
-            return $this;
-        }
-
         $header = $this->headerNames[$normalized];
 
         unset($this->headers[$header], $this->headerNames[$normalized]);