diff --git a/lib/rack/ssl-enforcer.rb b/lib/rack/ssl-enforcer.rb
index f4c3e58..b4f5b68 100644
--- a/lib/rack/ssl-enforcer.rb
+++ b/lib/rack/ssl-enforcer.rb
@@ -120,6 +120,8 @@ def destination_host
     def current_scheme
       if @request.env['HTTPS'] == 'on' || @request.env['HTTP_X_SSL_REQUEST'] == 'on'
         'https'
+      elsif @request.env['HTTP_FLY_FORWARDED_PROTO']
+        @request.env['HTTP_FLY_FORWARDED_PROTO']
       elsif @request.env['HTTP_X_FORWARDED_PROTO']
         @request.env['HTTP_X_FORWARDED_PROTO'].split(',')[0] || @request.scheme
       else