diff --git a/koans/about_inheritance.rb b/koans/about_inheritance.rb
index cafec3463..712daca55 100644
--- a/koans/about_inheritance.rb
+++ b/koans/about_inheritance.rb
@@ -31,7 +31,7 @@ def test_all_classes_ultimately_inherit_from_object
     assert_equal __, Chihuahua.ancestors.include?(Object)
   end
 
-  def test_subcases_inherit_behavior_from_parent_class
+  def test_subclasses_inherit_behavior_from_parent_class
     chico = Chihuahua.new("Chico")
     assert_equal __, chico.name
   end
diff --git a/src/about_inheritance.rb b/src/about_inheritance.rb
index f516cd602..73030c6ef 100644
--- a/src/about_inheritance.rb
+++ b/src/about_inheritance.rb
@@ -31,7 +31,7 @@ def test_all_classes_ultimately_inherit_from_object
     assert_equal __(true), Chihuahua.ancestors.include?(Object)
   end
 
-  def test_subcases_inherit_behavior_from_parent_class
+  def test_subclasses_inherit_behavior_from_parent_class
     chico = Chihuahua.new("Chico")
     assert_equal __("Chico"), chico.name
   end