diff --git a/spec/Prophecy/Exception/Prediction/AggregateExceptionSpec.php b/spec/Prophecy/Exception/Prediction/AggregateExceptionSpec.php
index e11c54b27..0c24b10fe 100644
--- a/spec/Prophecy/Exception/Prediction/AggregateExceptionSpec.php
+++ b/spec/Prophecy/Exception/Prediction/AggregateExceptionSpec.php
@@ -3,6 +3,7 @@
 namespace spec\Prophecy\Exception\Prediction;
 
 use PhpSpec\ObjectBehavior;
+use Prophecy\Exception\Prediction\FailedPredictionException;
 use Prophecy\Exception\Prediction\PredictionException;
 use Prophecy\Prophecy\ObjectProphecy;
 
@@ -30,18 +31,18 @@ function it_should_not_have_exceptions_at_the_beginning()
         $this->getExceptions()->shouldHaveCount(0);
     }
 
-    function it_should_append_exception_through_append_method(PredictionException $exception)
+    function it_should_append_exception_through_append_method()
     {
-        $exception->getMessage()->willReturn('Exception #1');
+        $exception = new FailedPredictionException();
 
         $this->append($exception);
 
         $this->getExceptions()->shouldReturn(array($exception));
     }
 
-    function it_should_update_message_during_append(PredictionException $exception)
+    function it_should_update_message_during_append()
     {
-        $exception->getMessage()->willReturn('Exception #1');
+        $exception = new FailedPredictionException('Exception #1');
 
         $this->append($exception);
 
@@ -52,12 +53,10 @@ function it_should_update_message_during_append_more_exceptions(
         PredictionException $exception1,
         PredictionException $exception2
     ) {
-        $exception1->getMessage()->willReturn('Exception #1');
-        $exception2->getMessage()->willReturn('Exception #2');
+        $exception1 = new FailedPredictionException('Exception #1');
+        $exception2 = new FailedPredictionException('Exception #2');
 
         $this->append($exception1);
-        $this->getMessage()->shouldReturn('Exception #1');
-
         $this->append($exception2);
         $this->getMessage()->shouldReturn("Exception #1\nException #2");
     }
diff --git a/src/Prophecy/Exception/Exception.php b/src/Prophecy/Exception/Exception.php
index ac9fe4dd9..416191284 100644
--- a/src/Prophecy/Exception/Exception.php
+++ b/src/Prophecy/Exception/Exception.php
@@ -17,10 +17,6 @@
  *
  * @author Konstantin Kudryashov <ever.zet@gmail.com>
  */
-interface Exception
+interface Exception extends \Throwable
 {
-    /**
-     * @return string
-     */
-    public function getMessage();
 }