diff --git a/koans/about_blocks.rb b/koans/about_blocks.rb
index 1bd2d13..0abee8f 100644
--- a/koans/about_blocks.rb
+++ b/koans/about_blocks.rb
@@ -60,7 +60,7 @@ class AboutBlocks < EdgeCase::Koan
 
   # ------------------------------------------------------------------
 
-  def test_block_can_effect_variables_in_the_code_where_they_are_created
+  def test_block_can_affect_variables_in_the_code_where_they_are_created
     value = :initial_value
     method_with_block { value = :modified_in_a_block }
     assert_equal __, value
diff --git a/src/about_blocks.rb b/src/about_blocks.rb
index 7330ca0..7fefcd9 100644
--- a/src/about_blocks.rb
+++ b/src/about_blocks.rb
@@ -60,7 +60,7 @@ class AboutBlocks < EdgeCase::Koan
 
   # ------------------------------------------------------------------
 
-  def test_block_can_effect_variables_in_the_code_where_they_are_created
+  def test_block_can_affect_variables_in_the_code_where_they_are_created
     value = :initial_value
     method_with_block { value = :modified_in_a_block }
     assert_equal __(:modified_in_a_block), value