diff --git a/gluefactory/models/utils/losses.py b/gluefactory/models/utils/losses.py
index cca17636..06c7958b 100644
--- a/gluefactory/models/utils/losses.py
+++ b/gluefactory/models/utils/losses.py
@@ -69,5 +69,5 @@ def nll_loss(self, log_assignment, data):
         weights[:, :m, :n] = positive
 
         weights[:, :m, -1] = neg0
-        weights[:, -1, :m] = neg1
+        weights[:, -1, :n] = neg1
         return weights