diff --git a/lib/Quox/Syntax/Var.idr b/lib/Quox/Syntax/Var.idr
index 3a589e2..2813cdc 100644
--- a/lib/Quox/Syntax/Var.idr
+++ b/lib/Quox/Syntax/Var.idr
@@ -45,7 +45,7 @@ parameters {auto _ : Pretty.HasEnv m}
   private
   prettyIndex : Nat -> m (Doc a)
   prettyIndex i =
-    ifUnicode (pretty $ pack $ map sup $ unpack $ show i) (":" <+> pretty i)
+    ifUnicode (pretty $ pack $ map sup $ unpack $ show i) ("#" <+> pretty i)
    where
     sup : Char -> Char
     sup c = case c of