diff --git a/doc/maintainers.rdoc b/doc/maintainers.rdoc
index 50b1053c3d..087feb5134 100644
--- a/doc/maintainers.rdoc
+++ b/doc/maintainers.rdoc
@@ -335,7 +335,7 @@ Zachary Scott (zzak)
 [ext/readline]
   TAKAO Kouji (kouji)
   https://github.com/ruby/readline-ext
-  http:://rubygems.org/gems/readline-ext
+  https://rubygems.org/gems/readline-ext
 [ext/stringio]
   Nobuyuki Nakada (nobu)
   https://github.com/ruby/stringio