diff --git a/Gemfile.lock b/Gemfile.lock
index cf28734799..92790586b2 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -121,8 +121,9 @@ GEM
       rest-client (~> 2.0)
     globalid (1.0.0)
       activesupport (>= 5.0)
-    govuk_app_config (4.3.0)
+    govuk_app_config (4.4.1)
       logstasher (>= 1.2.2, < 2.2.0)
+      prometheus_exporter (~> 2.0.2)
       puma (~> 5.0)
       sentry-rails (~> 4.5.0)
       sentry-ruby (~> 4.5.0)
@@ -208,6 +209,8 @@ GEM
     percy-capybara (5.0.0)
       capybara (>= 3)
     plek (4.0.0)
+    prometheus_exporter (2.0.2)
+      webrick
     pry (0.13.1)
       coderay (~> 1.1)
       method_source (~> 1.0)