diff --git a/lib/puma/rack/urlmap.rb b/lib/puma/rack/urlmap.rb
index a82c7ee8..adaf74a1 100644
--- a/lib/puma/rack/urlmap.rb
+++ b/lib/puma/rack/urlmap.rb
@@ -43,15 +43,17 @@ module Puma::Rack
     def call(env)
       path = env['PATH_INFO']
       script_name = env['SCRIPT_NAME']
-      hHost = env['HTTP_HOST']
-      sName = env['SERVER_NAME']
-      sPort = env['SERVER_PORT']
+      http_host = env['HTTP_HOST']
+      server_name = env['SERVER_NAME']
+      server_port = env['SERVER_PORT']
+
+      is_same_server = casecmp?(http_host, server_name) ||
+                    casecmp?(http_host, "#{server_name}:#{server_port}")
 
       @mapping.each do |host, location, match, app|
-        unless casecmp?(hHost, host) \
-            || casecmp?(sName, host) \
-            || (!host && (casecmp?(hHost, sName) ||
-                          casecmp?(hHost, sName+':'+sPort)))
+        unless casecmp?(http_host, host) \
+            || casecmp?(server_name, host) \
+            || (!host && is_same_server)
           next
         end
 
@@ -87,4 +89,3 @@ module Puma::Rack
     end
   end
 end
-