diff --git a/spec/rack_attack_spec.rb b/spec/rack_attack_spec.rb
index c8358352..40936017 100644
--- a/spec/rack_attack_spec.rb
+++ b/spec/rack_attack_spec.rb
@@ -11,6 +11,10 @@
     end
 
     it 'blocks requests with trailing slash' do
+      if Rack::Attack::PathNormalizer == Rack::Attack::FallbackPathNormalizer
+        skip "Normalization is only present on Rails"
+      end
+
       get '/foo/'
       _(last_response.status).must_equal 403
     end