diff --git a/lib/mini_profiler.rb b/lib/mini_profiler.rb
index cccbce90..40e81b1b 100644
--- a/lib/mini_profiler.rb
+++ b/lib/mini_profiler.rb
@@ -176,7 +176,8 @@ def call(env)
         end
       )
       if skip_it
-        return client_settings.handle_cookie(@app.call(env))
+        # preserve_cookie to ensure we don't deauthorize the request (delete the auth cookie) when loading assets
+        return client_settings.handle_cookie(@app.call(env), preserve_cookie: true)
       end
 
       skip_it = (@config.pre_authorize_cb && !@config.pre_authorize_cb.call(env))
diff --git a/lib/mini_profiler/client_settings.rb b/lib/mini_profiler/client_settings.rb
index 36855230..67a9ace5 100644
--- a/lib/mini_profiler/client_settings.rb
+++ b/lib/mini_profiler/client_settings.rb
@@ -39,13 +39,13 @@ def initialize(env, store, start)
 
       end
 
-      def handle_cookie(result)
+      def handle_cookie(result, preserve_cookie: false)
         status, headers, _body = result
 
         if (MiniProfiler.config.authorization_mode == :allow_authorized && !MiniProfiler.request_authorized?)
           # this is non-obvious, don't kill the profiling cookie on errors or short requests
           # this ensures that stuff that never reaches the rails stack does not kill profiling
-          if status.to_i >= 200 && status.to_i < 300 && ((Process.clock_gettime(Process::CLOCK_MONOTONIC) - @start) > 0.1)
+          if !preserve_cookie && status.to_i >= 200 && status.to_i < 300 && ((Process.clock_gettime(Process::CLOCK_MONOTONIC) - @start) > 0.1)
             discard_cookie!(headers)
           end
         else
diff --git a/lib/mini_profiler_rails/railtie.rb b/lib/mini_profiler_rails/railtie.rb
index 57379962..064ea190 100644
--- a/lib/mini_profiler_rails/railtie.rb
+++ b/lib/mini_profiler_rails/railtie.rb
@@ -165,7 +165,9 @@ def self.serves_static_assets?(app)
       return false
     end
 
-    if ::Rails.version >= "5.0.0"
+    if ::Rails.version >= "5.1.0"
+      ::Rails.configuration.public_file_server.enabled || ::Rails.configuration.assets.unknown_asset_fallback
+    elsif ::Rails.version >= "5.0.0"
       ::Rails.configuration.public_file_server.enabled
     elsif ::Rails.version >= "4.2.0"
       ::Rails.configuration.serve_static_files