diff --git a/testing/mozharness/mozharness/base/parallel.py b/testing/mozharness/mozharness/base/parallel.py
index 24f718dc58cc..99285156f607 100755
--- a/testing/mozharness/mozharness/base/parallel.py
+++ b/testing/mozharness/mozharness/base/parallel.py
@@ -26,7 +26,7 @@ class ChunkingMixin(object):
             possible_list = possible_list[:]
         length = len(possible_list)
         for c in range(1, total_chunks + 1):
-            n = length / total_chunks
+            n = length // total_chunks
             # If the total number of items isn't evenly divisible by the
             # number of chunks, we need to append one more onto some chunks
             if c <= (length % total_chunks):