diff --git a/numeric.c b/numeric.c
index affd60a182..dcf4cf5c04 100644
--- a/numeric.c
+++ b/numeric.c
@@ -829,7 +829,7 @@ rb_int_zero_p(VALUE num)
  *  Of the Core and Standard Library classes,
  *  Integer, Float, Rational, and Complex use this implementation.
  *
- * Related: #zero?
+ *  Related: #zero?
  *
  */