diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 22a6a61..03abb7f 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -229,6 +229,13 @@ integration-test-oni-browse-url:
     - package
   script: make integration-test-oni-browse-url TEST_ARCHIVE=$(realpath bin/)
 
+integration-test-oni-cpp:
+  stage: integration-test
+  image: registry.gitlab.com/ryuslash/emacs-config
+  dependencies:
+    - package
+  script: make integration-test-oni-cpp TEST_ARCHIVE=$(realpath bin/)
+
 integration-test-oni-docker:
   stage: integration-test
   image: registry.gitlab.com/ryuslash/emacs-config
diff --git a/test/integration/oni-cpp.bats b/test/integration/oni-cpp.bats
new file mode 100644
index 0000000..e8a9769
--- /dev/null
+++ b/test/integration/oni-cpp.bats
@@ -0,0 +1,11 @@
+#!/usr/bin/env bats
+
+@test "Opening a .cpp file loads oni-c++" {
+    run emacs -batch -l package -f package-initialize \
+        -visit test.cpp \
+        -eval "(prin1 (featurep 'oni-c++))"
+
+    echo "$output"
+
+    [ "$output" = "t" ]
+}