diff --git a/lib/psych/visitors/to_ruby.rb b/lib/psych/visitors/to_ruby.rb
index 79565dfc..d0bf0707 100644
--- a/lib/psych/visitors/to_ruby.rb
+++ b/lib/psych/visitors/to_ruby.rb
@@ -445,9 +445,6 @@ def deduplicate key
         end
       end
 
-      def merge_key hash, key, val
-      end
-
       def revive klass, node
         s = register(node, klass.allocate)
         init_with(s, revive_hash({}, node, true), node)
diff --git a/lib/psych/visitors/yaml_tree.rb b/lib/psych/visitors/yaml_tree.rb
index b6c86f4c..9c2c4aa4 100644
--- a/lib/psych/visitors/yaml_tree.rb
+++ b/lib/psych/visitors/yaml_tree.rb
@@ -496,9 +496,6 @@ def visit_hash_subclass o
         end
       end
 
-      def dump_list o
-      end
-
       def dump_exception o, msg
         tag = ['!ruby/exception', o.class.name].join ':'