diff --git a/Gemfile b/Gemfile
index e43b1d049..5ecea1b88 100644
--- a/Gemfile
+++ b/Gemfile
@@ -13,7 +13,7 @@ gem "govspeak"
 gem "govuk_ab_testing"
 gem "govuk_app_config"
 gem "govuk_document_types"
-gem "govuk_publishing_components"
+gem "govuk_publishing_components", git: "https://github.com/alphagov/govuk_publishing_components.git", branch: "spike-font-size-changes-2"
 gem "plek"
 gem "rails-i18n"
 gem "rails_translation_manager"
diff --git a/Gemfile.lock b/Gemfile.lock
index f9453146c..ca0530a02 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,3 +1,18 @@
+GIT
+  remote: https://github.com/alphagov/govuk_publishing_components.git
+  revision: 844ca9b18bd6f77b8c8183c9ef4cb89d8dec6357
+  branch: spike-font-size-changes-2
+  specs:
+    govuk_publishing_components (38.0.1)
+      govuk_app_config
+      govuk_personalisation (>= 0.7.0)
+      kramdown
+      plek
+      rails (>= 6)
+      rouge
+      sprockets (>= 3)
+      sprockets-rails
+
 GEM
   remote: https://rubygems.org/
   specs:
@@ -213,15 +228,6 @@ GEM
     govuk_personalisation (0.16.0)
       plek (>= 1.9.0)
       rails (>= 6, < 8)
-    govuk_publishing_components (38.0.1)
-      govuk_app_config
-      govuk_personalisation (>= 0.7.0)
-      kramdown
-      plek
-      rails (>= 6)
-      rouge
-      sprockets (>= 3)
-      sprockets-rails
     govuk_schemas (5.0.0)
       json-schema (>= 2.8, < 4.4)
     govuk_test (4.0.2)
@@ -781,7 +787,7 @@ DEPENDENCIES
   govuk_ab_testing
   govuk_app_config
   govuk_document_types
-  govuk_publishing_components
+  govuk_publishing_components!
   govuk_schemas
   govuk_test
   i18n-coverage