diff --git a/lib/rack/pact_broker/accepts_html_filter.rb b/lib/rack/pact_broker/accepts_html_filter.rb
index d0ff21e8c..88b06f301 100644
--- a/lib/rack/pact_broker/accepts_html_filter.rb
+++ b/lib/rack/pact_broker/accepts_html_filter.rb
@@ -1,4 +1,5 @@
-# Decides whether this is a browser request or a request for the API
+# Decides whether this is a request for the UI or a request for the API
+
 module Rack
   module PactBroker
     class AcceptsHtmlFilter
@@ -7,24 +8,29 @@ def initialize app
       end
 
       def call env
-        if accepts_web_content_types_and_not_api_media env
+        if request_for_ui_resource? env
           @app.call(env)
         else
           [404, {},[]]
         end
       end
 
-      def accepts_web_content_types_and_not_api_media env
-        accept = env['HTTP_ACCEPT'] || ''
-        accepts_web_content_types(accept) && !accepts_api_content_types(accept)
+      private
+
+      def request_for_ui_resource? env
+        request_for_file?(env) || accepts_html?(env)
       end
 
-      def accepts_web_content_types(accept)
-        accept.include?("*/*") || accept.include?("html") || accept.include?("text/css") || accept.include?("text/javascript")
+      def request_for_file?(env)
+        if last_segment = env['PATH_INFO'].split("/").last
+          last_segment.include?(".")
+        else
+          false
+        end
       end
 
-      def accepts_api_content_types accept
-        accept.include?("json") || accept.include?("csv")
+      def accepts_html?(env)
+        (env['HTTP_ACCEPT'] || '').include?("text/html")
       end
     end
   end
diff --git a/spec/lib/rack/pact_broker/accepts_html_filter_spec.rb b/spec/lib/rack/pact_broker/accepts_html_filter_spec.rb
new file mode 100644
index 000000000..39c1dc0fa
--- /dev/null
+++ b/spec/lib/rack/pact_broker/accepts_html_filter_spec.rb
@@ -0,0 +1,43 @@
+require 'rack/pact_broker/accepts_html_filter'
+require 'rack/test'
+
+module Rack
+  module PactBroker
+    describe AcceptsHtmlFilter do
+      include Rack::Test::Methods
+
+      describe "#call" do
+        let(:target_app) { double('target_app', call: [200, {}, []]) }
+        let(:app) { AcceptsHtmlFilter.new(target_app) }
+        let(:path) { "/" }
+        let(:accept) { "text/html" }
+
+        subject { get path, nil, { "HTTP_ACCEPT" => accept } }
+
+        context "when the Accept header includes text/html" do
+          it "forwards the request to the target app" do
+            expect(target_app).to receive(:call)
+            subject
+          end
+        end
+
+        context "when the request is for a file" do
+          let(:path) { "/blah/foo.css" }
+
+          it "forwards the request to the target app" do
+            expect(target_app).to receive(:call)
+            subject
+          end
+        end
+
+        context "when the request is not for a file, and the Accept header does not include text/html" do
+          let(:accept) { "application/hal+json, */*" }
+
+          it "returns a 404" do
+            expect(subject.status).to eq 404
+          end
+        end
+      end
+    end
+  end
+end