diff --git a/lib/mutant/ast/named_children.rb b/lib/mutant/ast/named_children.rb
index 1657da7e..7b3bd857 100644
--- a/lib/mutant/ast/named_children.rb
+++ b/lib/mutant/ast/named_children.rb
@@ -79,6 +79,8 @@ module Mutant
         # Define private method
         #
         # @param [Symbol] name
+        #
+        # @return [undefined]
         def define_private_method(name, &block)
           define_method(name, &block)
           private(name)
diff --git a/lib/mutant/reporter/sequence.rb b/lib/mutant/reporter/sequence.rb
index 154eae55..6fe51653 100644
--- a/lib/mutant/reporter/sequence.rb
+++ b/lib/mutant/reporter/sequence.rb
@@ -13,6 +13,9 @@ module Mutant
         end
       end
 
+      # Minimum reporter delay
+      #
+      # @return [Float]
       def delay
         reporters.map(&:delay).min
       end