diff --git a/Gemfile b/Gemfile
index d14fcb16c..f86d8bed2 100644
--- a/Gemfile
+++ b/Gemfile
@@ -156,7 +156,7 @@ group :test do
   # launch browser when inspecting capybara specs
   gem "launchy"
   gem "timecop"
-  gem "undercover", "~> 0.5.0"
+  gem "undercover", "~> 0.6.3"
   gem "webmock"
 
   gem "rubocop-govuk", require: false
diff --git a/Gemfile.lock b/Gemfile.lock
index 9bf1de51b..8716ce3ba 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -125,7 +125,7 @@ GEM
       erubi (~> 1.4)
       parser (>= 2.4)
       smart_properties
-    bigdecimal (3.1.8)
+    bigdecimal (3.1.9)
     bindata (2.5.0)
     bindex (0.8.1)
     bootsnap (1.18.4)
@@ -634,9 +634,9 @@ GEM
     tzinfo (2.0.6)
       concurrent-ruby (~> 1.0)
     uber (0.1.0)
-    undercover (0.5.0)
+    undercover (0.6.3)
       bigdecimal
-      imagen (>= 0.1.8)
+      imagen (>= 0.2.0)
       rainbow (>= 2.1, < 4.0)
       rugged (>= 0.27, < 1.8)
     unicode-display_width (2.6.0)
@@ -751,7 +751,7 @@ DEPENDENCIES
   syntax_tree-rbs
   timecop
   tzinfo-data
-  undercover (~> 0.5.0)
+  undercover (~> 0.6.3)
   view_component
   web-console
   webmock