diff --git a/lib/spy.js b/lib/spy.js
index 40e56c3..6b5db55 100644
--- a/lib/spy.js
+++ b/lib/spy.js
@@ -269,7 +269,7 @@ module.exports = function (chai, _) {
 
       this.assert(
           passed > 0
-        , 'expected ' + this._obj + ' to have been called with #{exp}'
+        , 'expected ' + this._obj + ' to have been called with #{exp} but got #{act}'
         , 'expected ' + this._his + ' to have not been called with #{exp} but got ' + passed + ' times'
         , args
       );