diff --git a/app/helpers/theme_helper.rb b/app/helpers/theme_helper.rb
index 06a1ff39..1202588c 100644
--- a/app/helpers/theme_helper.rb
+++ b/app/helpers/theme_helper.rb
@@ -23,7 +23,7 @@ module ThemeHelper
           end
         elsif hash.is_a? Hash
           hash.each do |k, v|
-            next unless v.is_a? Fixnum
+            next unless v.is_a? Integer
 
             self.instance_variable_set "@#{k}", ('#' + ('0000000' + hash[k].to_s(16))[-6, 6])
           end