diff --git a/.changesets/add-sinatra_sanitized_routes-option.md b/.changesets/add-sinatra_sanitized_routes-option.md
new file mode 100644
index 000000000..5fd678695
--- /dev/null
+++ b/.changesets/add-sinatra_sanitized_routes-option.md
@@ -0,0 +1,6 @@
+---
+bump: "patch"
+type: "add"
+---
+
+Add sinatra_sanitized_routes option to store sanitized routes instead of the real request path in the Transaction's metadata. This can be useful if there's PII or other sensitive data in the app's request paths. Set `sinatra_sanitized_routes` to `true` in the AppSignal config to enable this behavior and store the route definition rather than the real request path as metadata. We also recommend changing the `request_headers` config option to not include any headers that also include the real request path.
diff --git a/lib/appsignal/config.rb b/lib/appsignal/config.rb
index c889b049d..9055a71f6 100644
--- a/lib/appsignal/config.rb
+++ b/lib/appsignal/config.rb
@@ -44,6 +44,7 @@ class Config
       ],
       :send_environment_metadata => true,
       :send_params => true,
+      :sinatra_sanitized_routes => false,
       :transaction_debug_mode => false
     }.freeze
 
@@ -99,6 +100,7 @@ class Config
       "APPSIGNAL_SEND_ENVIRONMENT_METADATA" => :send_environment_metadata,
       "APPSIGNAL_SEND_PARAMS" => :send_params,
       "APPSIGNAL_SEND_SESSION_DATA" => :send_session_data,
+      "APPSIGNAL_SINATRA_SANITIZED_ROUTES" => :sinatra_sanitized_routes,
       "APPSIGNAL_SKIP_SESSION_DATA" => :skip_session_data,
       "APPSIGNAL_STATSD_PORT" => :statsd_port,
       "APPSIGNAL_TRANSACTION_DEBUG_MODE" => :transaction_debug_mode,
@@ -144,6 +146,7 @@ class Config
       APPSIGNAL_SEND_ENVIRONMENT_METADATA
       APPSIGNAL_SEND_PARAMS
       APPSIGNAL_SEND_SESSION_DATA
+      APPSIGNAL_SINATRA_SANITIZED_ROUTES
       APPSIGNAL_SKIP_SESSION_DATA
       APPSIGNAL_TRANSACTION_DEBUG_MODE
     ].freeze
diff --git a/lib/appsignal/rack/sinatra_instrumentation.rb b/lib/appsignal/rack/sinatra_instrumentation.rb
index 678052c9a..be4aaa882 100644
--- a/lib/appsignal/rack/sinatra_instrumentation.rb
+++ b/lib/appsignal/rack/sinatra_instrumentation.rb
@@ -70,7 +70,13 @@ def call_with_appsignal_monitoring(env)
             transaction.set_error(env["sinatra.error"])
           end
           transaction.set_action_if_nil(action_name(env))
-          transaction.set_metadata("path", request.path)
+          path =
+            if Appsignal.config[:sinatra_sanitized_routes]
+              sanitized_route(env)
+            else
+              request.path
+            end
+          transaction.set_metadata("path", path)
           transaction.set_metadata("method", request.request_method)
           transaction.set_http_or_background_queue_start
           Appsignal::Transaction.complete_current!
@@ -90,6 +96,13 @@ def action_name(env)
 
       private
 
+      def sanitized_route(env)
+        return unless env["sinatra.route"]
+
+        _method, route = env["sinatra.route"].split
+        route
+      end
+
       def raise_errors?(app)
         app.respond_to?(:settings) &&
           app.settings.respond_to?(:raise_errors) &&
diff --git a/spec/integration/diagnose b/spec/integration/diagnose
index 994514807..19cfce561 160000
--- a/spec/integration/diagnose
+++ b/spec/integration/diagnose
@@ -1 +1 @@
-Subproject commit 994514807b4c902587a199dfb315754e613372c3
+Subproject commit 19cfce561345318a7f892107c3eec01ee3eb70de
diff --git a/spec/lib/appsignal/config_spec.rb b/spec/lib/appsignal/config_spec.rb
index e3f94fe08..5032ba9a8 100644
--- a/spec/lib/appsignal/config_spec.rb
+++ b/spec/lib/appsignal/config_spec.rb
@@ -183,6 +183,7 @@
         :send_environment_metadata      => true,
         :send_params                    => true,
         :send_session_data              => true,
+        :sinatra_sanitized_routes       => false,
         :transaction_debug_mode         => false
       )
     end
diff --git a/spec/lib/appsignal/rack/sinatra_instrumentation_spec.rb b/spec/lib/appsignal/rack/sinatra_instrumentation_spec.rb
index 279b45a9b..8805d7d4b 100644
--- a/spec/lib/appsignal/rack/sinatra_instrumentation_spec.rb
+++ b/spec/lib/appsignal/rack/sinatra_instrumentation_spec.rb
@@ -260,6 +260,24 @@ def make_request_with_error(env, error)
             )
           )
         end
+
+        context "with sinatra_sanitized_routes=true" do
+          before { Appsignal.config[:sinatra_sanitized_routes] = true }
+          after { Appsignal.config[:sinatra_sanitized_routes] = false }
+          let(:env) { { "sinatra.route" => "GET /some/:path", "REQUEST_METHOD" => "GET" } }
+
+          it "sets the path as the sanitized defined route" do
+            make_request(env)
+
+            expect(created_transactions.count).to eq(1)
+            expect(last_transaction.to_h).to include(
+              "metadata" => {
+                "method" => "GET",
+                "path" => "/some/:path"
+              }
+            )
+          end
+        end
       end
 
       context "with queue start" do