diff --git a/assert/assertions.go b/assert/assertions.go
index a82c781..bc8ac6c 100644
--- a/assert/assertions.go
+++ b/assert/assertions.go
@@ -214,7 +214,7 @@ func Implements(t TestingT, interfaceObject interface{}, object interface{}, msg
 	interfaceType := reflect.TypeOf(interfaceObject).Elem()
 
 	if !reflect.TypeOf(object).Implements(interfaceType) {
-		return Fail(t, fmt.Sprintf("Object must implement %v", interfaceType), msgAndArgs...)
+		return Fail(t, fmt.Sprintf("%T must implement %v", object, interfaceType), msgAndArgs...)
 	}
 
 	return true