diff --git a/NEWS.md b/NEWS.md
index d2bb130e0..68e8ed472 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -34,6 +34,10 @@
 * Fix `validate_inclusion_of` used with `with_message` so that it fails if given
   a message that does not match the message on the validation. ([#598])
 
+* Fix `route` matcher so that when controller and action are specified in hash
+  notation (e.g. `posts#show`), route parameters such as `id` do not need to be
+  specified as a string but may be specified as a number as well ([#602]).
+
 ### Features
 
 * Add ability to test `:primary_key` option on associations. ([#597])
@@ -51,6 +55,7 @@
 [#597]: https://github.com/thoughtbot/shoulda-matchers/pull/597
 [#537]: https://github.com/thoughtbot/shoulda-matchers/pull/537
 [#598]: https://github.com/thoughtbot/shoulda-matchers/pull/598
+[#602]: https://github.com/thoughtbot/shoulda-matchers/pull/602
 
 # 2.7.0
 
diff --git a/lib/shoulda/matchers/action_controller/route_params.rb b/lib/shoulda/matchers/action_controller/route_params.rb
index 8d7afb969..a1cd5e65e 100644
--- a/lib/shoulda/matchers/action_controller/route_params.rb
+++ b/lib/shoulda/matchers/action_controller/route_params.rb
@@ -24,14 +24,19 @@ def controller_and_action_given_as_string?
         end
 
         def extract_params_from_string
-          params = args[1] || {}
           controller, action = args[0].split('#')
-          params.merge!(controller: controller, action: action)
+          params = (args[1] || {}).merge(controller: controller, action: action)
+          stringify_values(params)
         end
 
         def stringify_params
-          args[0].each do |key, value|
-            args[0][key] = stringify(value)
+          stringify_values(args[0])
+        end
+
+        def stringify_values(hash)
+          hash.inject({}) do |hash_copy, (key, value)|
+            hash_copy[key] = stringify(value)
+            hash_copy
           end
         end
 
diff --git a/spec/unit/shoulda/matchers/action_controller/route_matcher_spec.rb b/spec/unit/shoulda/matchers/action_controller/route_matcher_spec.rb
index f492f2299..fa0b6eb51 100644
--- a/spec/unit/shoulda/matchers/action_controller/route_matcher_spec.rb
+++ b/spec/unit/shoulda/matchers/action_controller/route_matcher_spec.rb
@@ -56,6 +56,14 @@
           to route(:get, "/#{controller_name}").
           to("#{controller_name}#index")
       end
+
+      context 'when route has parameters' do
+        it 'accepts a non-string parameter' do
+          expect(controller_with_defined_routes).
+            to route(:get, "/#{controller_name}/1").
+            to("#{controller_name}#show", id: 1)
+        end
+      end
     end
 
     def controller_with_defined_routes