diff --git a/ractor.rb b/ractor.rb
index 39dc8c9dc1..9f784a7111 100644
--- a/ractor.rb
+++ b/ractor.rb
@@ -889,7 +889,7 @@ class Ractor
   end
 
   # internal method
-  def self._require feature
+  def self._require feature # :nodoc:
     if main?
       super feature
     else
@@ -901,11 +901,11 @@ class Ractor
     private
 
     # internal method that is called when the first "Ractor.new" is called
-    def _activated
+    def _activated # :nodoc:
       Kernel.prepend Module.new{|m|
         m.set_temporary_name '<RactorRequire>'
 
-        def require feature
+        def require feature # :nodoc: -- otherwise RDoc outputs it as a class method
           if Ractor.main?
             super
           else