diff --git a/zipline/pipeline/factors/factor.py b/zipline/pipeline/factors/factor.py
index c3af8e04..4f1751e9 100644
--- a/zipline/pipeline/factors/factor.py
+++ b/zipline/pipeline/factors/factor.py
@@ -489,7 +489,7 @@ class CustomFactor(RequiredWindowLengthMixin, CustomTermMixin, Factor):
     Examples
     --------
 
-    A CustomFactor with pre-declared defaults:
+    A CustomFactor with pre-declared defaults::
 
         class TenDayRange(CustomFactor):
             """