diff --git a/magnet_loss/magnet_tools.py b/magnet_loss/magnet_tools.py
index 46d1c10..da37761 100644
--- a/magnet_loss/magnet_tools.py
+++ b/magnet_loss/magnet_tools.py
@@ -165,4 +165,4 @@ def get_cluster_ind(self, c, i):
 
     def get_class_ind(self, c):
         """Given a cluster index return the class index."""
-        return c / self.k
+        return c // self.k