diff --git a/lib/letter_avatar/configuration.rb b/lib/letter_avatar/configuration.rb
index c9f0a35..4f25c1e 100644
--- a/lib/letter_avatar/configuration.rb
+++ b/lib/letter_avatar/configuration.rb
@@ -21,7 +21,7 @@ module LetterAvatar
     end
 
     def colors_palette=(v)
-      @colors_palette = v if v.in?(Colors::PALETTES)
+      @colors_palette = v if Colors::PALETTES.include?(v)
     end
 
     def weight
--
libgit2 0.21.0