diff --git a/lib/Dispatcher.php b/lib/Dispatcher.php
index 5f045df..6354059 100644
--- a/lib/Dispatcher.php
+++ b/lib/Dispatcher.php
@@ -133,7 +133,9 @@ public function dispatch($msg)
                                 // Fallback for php 7.0, which is still supported (and doesn't have nullable).
                                 $class = (string)$paramType;
                             }
-                            $value = $this->mapper->map($value, new $class());
+                            if ($class !== 'mixed') {
+                                $value = $this->mapper->map($value, new $class());
+                            }
                         }
                     } else if (is_array($value) && isset($docBlock)) {
                         // Get the array type from the DocBlock
diff --git a/tests/DispatcherTest.php b/tests/DispatcherTest.php
index 8b54d06..8b223a9 100644
--- a/tests/DispatcherTest.php
+++ b/tests/DispatcherTest.php
@@ -57,6 +57,14 @@ public function testCallMethodWithMissingArgument()
         $this->assertEquals($this->calls, [new MethodCall('someMethodWithDifferentlyTypedArgs', [0 => null, 1 => 0])]);
     }
 
+    /*public function testCallMethodWithMixedParam()
+    {
+        $result = $this->dispatcher->dispatch((string)new Request(1, 'someMethodWithMixedTypeParam', ['arg' => new Argument('whatever')]));
+        $this->assertEquals('Hello World', $result);
+        $this->assertIsObject($this->calls[0]->args[0]);
+        $this->assertEquals($this->calls, [new MethodCall('someMethodWithMixedTypeParam', [0 => $this->calls[0]->args[0]])]);
+    }*/
+
     public function testCallMethodWithUnionTypeParamTag()
     {
         $result = $this->dispatcher->dispatch((string)new Request(1, 'someMethodWithUnionTypeParamTag', ['arg' => [new Argument('whatever')]]));
diff --git a/tests/Target.php b/tests/Target.php
index 84ece52..5ea4b6b 100644
--- a/tests/Target.php
+++ b/tests/Target.php
@@ -44,6 +44,12 @@ public function someMethodWithUnionTypeParamTag($arg)
         return 'Hello World';
     }
 
+    /*public function someMethodWithMixedTypeParam(mixed $arg)
+    {
+        $this->calls[] = new MethodCall('someMethodWithMixedTypeParam', func_get_args());
+        return 'Hello World';
+    }*/
+
     public function someMethodWithDifferentlyTypedArgs(string $arg1 = null, int $arg2 = null)
     {
         $this->calls[] = new MethodCall('someMethodWithDifferentlyTypedArgs', func_get_args());