diff --git a/_pytest/python_api.py b/_pytest/python_api.py
index 91605aa55..acc3ea286 100644
--- a/_pytest/python_api.py
+++ b/_pytest/python_api.py
@@ -133,7 +133,7 @@ class ApproxMapping(ApproxBase):
             for k,v in self.expected.items()))
 
     def __eq__(self, actual):
-        if actual.keys() != self.expected.keys():
+        if set(actual.keys()) != set(self.expected.keys()):
             return False
 
         return ApproxBase.__eq__(self, actual)