diff --git a/lib/better_errors/error_page.rb b/lib/better_errors/error_page.rb
index 40cccb1c..29989969 100644
--- a/lib/better_errors/error_page.rb
+++ b/lib/better_errors/error_page.rb
@@ -84,7 +84,7 @@ def rails_params
     end
 
     def uri_prefix
-      env["SCRIPT_NAME"] || ""
+      BetterErrors::Middleware.internal_url_prefix + env["SCRIPT_NAME"] || ""
     end
 
     def request_path
diff --git a/lib/better_errors/middleware.rb b/lib/better_errors/middleware.rb
index 1e4f8e2d..fd8992e3 100644
--- a/lib/better_errors/middleware.rb
+++ b/lib/better_errors/middleware.rb
@@ -39,6 +39,17 @@ def self.allow_ip!(addr)
     allow_ip! "127.0.0.0/8"
     allow_ip! "::1/128" rescue nil # windows ruby doesn't have ipv6 support
 
+    # Set this if you are running your app under a path which it is not aware of.
+    @internal_url_prefix = ""
+
+    def self.internal_url_prefix
+      @internal_url_prefix
+    end
+
+    def self.internal_url_prefix=(value)
+      @internal_url_prefix = value
+    end
+
     # A new instance of BetterErrors::Middleware
     #
     # @param app      The Rack app/middleware to wrap with Better Errors