diff --git a/baselines/deepq/utils.py b/baselines/deepq/utils.py
index 5176f32..2065073 100644
--- a/baselines/deepq/utils.py
+++ b/baselines/deepq/utils.py
@@ -20,7 +20,7 @@ class TfInput(object):
         """
         raise NotImplementedError
 
-    def make_feed_dict(data):
+    def make_feed_dict(self, data):
         """Given data input it to the placeholder(s)."""
         raise NotImplementedError