diff --git a/lib/weary/middleware/hmac_auth.rb b/lib/weary/middleware/hmac_auth.rb
index <HASH>..<HASH> 100644
--- a/lib/weary/middleware/hmac_auth.rb
+++ b/lib/weary/middleware/hmac_auth.rb
@@ -28,7 +28,7 @@ module Weary
           # there's no difference in the headers when it's authenticated.
           if ['POST', 'PUT'].include? e['REQUEST_METHOD']
             e.update 'CONTENT_TYPE' => 'application/x-www-form-urlencoded'
-          elsif e['REQUEST_METHOD'] == 'GET' && e['CONTENT_TYPE'].blank?
+          elsif e['REQUEST_METHOD'] == 'GET' && e['CONTENT_TYPE'].to_s == ''
             e.update 'CONTENT_TYPE' => 'text/plain'
           end
         end
Remove call to blank? active_support method

Active support should not be a dependency.