diff --git a/templates/repo/widget/inline-diff.cassius b/templates/repo/widget/inline-diff.cassius
index e6409fd..b2179a1 100644
--- a/templates/repo/widget/inline-diff.cassius
+++ b/templates/repo/widget/inline-diff.cassius
@@ -15,6 +15,7 @@
 
 pre
     margin: 0px
+    tab-size: 4
 
 .lines
     font-family: monospace