diff --git a/reverse.py b/reverse.py
index 6c4b271..bd4ca0b 100644
--- a/reverse.py
+++ b/reverse.py
@@ -58,7 +58,7 @@ def reverse_zone(network):
     if network.version == 4:
         boundary = 8  # break to the byte
     elif network.version == 6:
-        boundary = 4  # break to the nimble
+        boundary = 4  # break to the nibble
 
     assert network.prefixlen % boundary == 0
     length = (network.prefixlen // boundary)