diff --git a/Gemfile b/Gemfile
index 32c6366faf..65e344e8b3 100644
--- a/Gemfile
+++ b/Gemfile
@@ -11,7 +11,7 @@ gem "gds-api-adapters"
 gem "govuk_ab_testing"
 gem "govuk_app_config"
 gem "govuk_personalisation"
-gem "govuk_publishing_components"
+gem "govuk_publishing_components", git: "https://github.com/alphagov/govuk_publishing_components.git", branch: "spike-font-size-changes-2"
 gem "htmlentities"
 gem "invalid_utf8_rejector"
 gem "plek"
diff --git a/Gemfile.lock b/Gemfile.lock
index ce153f1587..285a106c3e 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,3 +1,18 @@
+GIT
+  remote: https://github.com/alphagov/govuk_publishing_components.git
+  revision: 4b65e6cdbdbb78f85122c2d176a368c0b5411ff7
+  branch: spike-font-size-changes-2
+  specs:
+    govuk_publishing_components (37.3.0)
+      govuk_app_config
+      govuk_personalisation (>= 0.7.0)
+      kramdown
+      plek
+      rails (>= 6)
+      rouge
+      sprockets (>= 3)
+      sprockets-rails
+
 GEM
   remote: https://rubygems.org/
   specs:
@@ -167,15 +182,6 @@ GEM
     govuk_personalisation (0.15.0)
       plek (>= 1.9.0)
       rails (>= 6, < 8)
-    govuk_publishing_components (37.3.0)
-      govuk_app_config
-      govuk_personalisation (>= 0.7.0)
-      kramdown
-      plek
-      rails (>= 6)
-      rouge
-      sprockets (>= 3)
-      sprockets-rails
     govuk_schemas (4.7.0)
       json-schema (>= 2.8, < 4.2)
     govuk_test (4.0.2)
@@ -707,7 +713,7 @@ DEPENDENCIES
   govuk_ab_testing
   govuk_app_config
   govuk_personalisation
-  govuk_publishing_components
+  govuk_publishing_components!
   govuk_schemas
   govuk_test
   htmlentities