diff --git a/src/pyj/read_book/cfi.pyj b/src/pyj/read_book/cfi.pyj
index 862f72b816..537a20a6a2 100644
--- a/src/pyj/read_book/cfi.pyj
+++ b/src/pyj/read_book/cfi.pyj
@@ -467,7 +467,7 @@ def create_cfi_cmp(key_map):
             diff = a.steps[i] - b.steps[i]
             if diff is not 0:
                 return diff
-        diff = a.length - b.length
+        diff = a.steps.length - b.steps.length
         if diff is not 0:
             return diff