diff --git a/lib/galaxy/util/expressions.py b/lib/galaxy/util/expressions.py
index c46c6b0dbaa..fe839cb77ee 100644
--- a/lib/galaxy/util/expressions.py
+++ b/lib/galaxy/util/expressions.py
@@ -27,4 +27,6 @@ class ExpressionContext( object, DictMixin ):
         if self.parent is not None and key in self.parent:
             return True
         return False
+    def __str__( self ):
+        return str( self.dict )