diff --git a/string.c b/string.c
index bd722b8ec2..70419a88c2 100644
--- a/string.c
+++ b/string.c
@@ -3601,7 +3601,9 @@ rb_str_freeze(VALUE str)
  * without warning issuance.
  *
  * Otherwise returns <tt>self.dup</tt>, which is not frozen.
- */
+ *
+ * Related: see {Freezing/Unfreezing}[rdoc-ref:String@Freezing-2FUnfreezing].
+s */
 static VALUE
 str_uplus(VALUE str)
 {