diff --git a/sparselearning/funcs.py b/sparselearning/funcs.py
index 562f828..2000b44 100644
--- a/sparselearning/funcs.py
+++ b/sparselearning/funcs.py
@@ -159,7 +159,7 @@ def magnitude_and_negativity_prune(masking, mask, weight, name):
 
     # remove the most negative weights
     x, idx = torch.sort(weight.data.view(-1))
-    mask.data.view(-1)[idx[:math.ceil(num_remove/2.0)]] = 0.0
+    mask.data.view(-1)[idx[math.ceil(num_remove/2.0):]] = 0.0
 
     return mask