diff --git a/app/models/track.rb b/app/models/track.rb
index d7329104b8..e18549f817 100644
--- a/app/models/track.rb
+++ b/app/models/track.rb
@@ -37,7 +37,7 @@ class Track < ApplicationRecord
   # A list here rather than a lookup of the published manifest, because
   # isolating a page is a deliberate per-track decision, not a side effect of
   # something landing in S3.
-  CLIENT_SIDE_TEST_RUNNER_SLUGS = %w[jq].freeze
+  CLIENT_SIDE_TEST_RUNNER_SLUGS = %w[jq cpp].freeze
   def client_side_test_runner? = CLIENT_SIDE_TEST_RUNNER_SLUGS.include?(slug)
 
   delegate :about, :snippet,
diff --git a/test/models/track_test.rb b/test/models/track_test.rb
index 8da3852c0e..ef9f9c34c0 100644
--- a/test/models/track_test.rb
+++ b/test/models/track_test.rb
@@ -29,6 +29,11 @@ class TrackTest < ActiveSupport::TestCase
     assert_equal track.slug, track.to_param
   end
 
+  test "client_side_test_runner?" do
+    assert create(:track, slug: "cpp").client_side_test_runner?
+    refute create(:track, slug: "ruby").client_side_test_runner?
+  end
+
   test "highlightjs_language uses slug if nil" do
     track = create :track, highlightjs_language: nil
     assert_equal 'ruby', track.highlightjs_language