diff --git a/simpleflow/exceptions.py b/simpleflow/exceptions.py
index 5c07e323c..fc0bf17a1 100644
--- a/simpleflow/exceptions.py
+++ b/simpleflow/exceptions.py
@@ -37,7 +37,7 @@ def __init__(self, reason, details=None):
         self.details = None
 
     def __repr__(self):
-        return '{}(reason="{}", details="{}")'.format(
+        return '{}(reason="{}")'.format(
             self.__class__.__name__,
             self.reason,
             self.details)