diff --git a/classes/MockDelegateFunction.tpl b/classes/MockDelegateFunction.tpl
index ed47624..7887e96 100644
--- a/classes/MockDelegateFunction.tpl
+++ b/classes/MockDelegateFunction.tpl
@@ -10,7 +10,7 @@ use phpmock\functions\FunctionProvider;
  * @license http://www.wtfpl.net/txt/copying/ WTFPL
  * @internal
  */
-abstract class MockDelegateFunction implements FunctionProvider
+class MockDelegateFunction implements FunctionProvider
 {
     
     /**
@@ -18,10 +18,16 @@ abstract class MockDelegateFunction implements FunctionProvider
      *
      * @return mixed Returns the function output.
      */
-    abstract public function delegate({signatureParameters});
+    public function delegate({signatureParameters})
+    {
+    }
 
     public function getCallable()
     {
         return [$this, "delegate"];
     }
+
+    public function {functionName}()
+    {
+    }
 }
diff --git a/classes/MockDelegateFunctionBuilder.php b/classes/MockDelegateFunctionBuilder.php
index da36f3b..fa297c8 100644
--- a/classes/MockDelegateFunctionBuilder.php
+++ b/classes/MockDelegateFunctionBuilder.php
@@ -52,11 +52,13 @@ public function build($functionName = null)
         $parameterBuilder->build($functionName === null ? '' : $functionName);
         $signatureParameters = $parameterBuilder->getSignatureParameters();
 
+        $populatedFunctionName = $functionName === null ? '_dummy' : $functionName;
+
         /**
          * If a class with the same signature exists, it is considered equivalent
          * to the generated class.
          */
-        $hash = md5($signatureParameters);
+        $hash = md5($populatedFunctionName . $signatureParameters);
         $this->namespace = __NAMESPACE__ . $hash;
         if (class_exists($this->getFullyQualifiedClassName())) {
             return;
@@ -65,6 +67,7 @@ public function build($functionName = null)
         $data = [
             "namespace"           => $this->namespace,
             "signatureParameters" => $signatureParameters,
+            "functionName"        => $populatedFunctionName,
         ];
         $this->template->setVar($data, false);
         $definition = $this->template->render();