diff --git a/core/drupalci.yml b/core/drupalci.yml
index 94aa2ad22f..0bae7377af 100644
--- a/core/drupalci.yml
+++ b/core/drupalci.yml
@@ -15,7 +15,7 @@ build:
       # deprecated code.
       run_tests.phpunit:
         types: 'PHPUnit-Unit'
-        testgroups: '--all'
+        testgroups: '--module ckeditor5'
         suppress-deprecations: false
         halt-on-fail: false
       run_tests.kernel:
@@ -27,18 +27,18 @@ build:
         # Limit concurrency due to disk space concerns.
         concurrency: 15
         types: 'PHPUnit-Build'
-        testgroups: '--all'
+        testgroups: '--module ckeditor5'
         suppress-deprecations: false
         halt-on-fail: false
       run_tests.functional:
         types: 'PHPUnit-Functional'
-        testgroups: '--all'
+        testgroups: '--module ckeditor5'
         suppress-deprecations: false
         halt-on-fail: false
       run_tests.javascript:
         concurrency: 15
         types: 'PHPUnit-FunctionalJavascript'
-        testgroups: '--all'
+        testgroups: '--module ckeditor5'
         suppress-deprecations: false
         halt-on-fail: false
       # Run nightwatch testing.
diff --git a/core/package.json b/core/package.json
index c14f58a08c..cc55f438eb 100644
--- a/core/package.json
+++ b/core/package.json
@@ -18,7 +18,7 @@
     "lint:css": "stylelint \"**/*.css\"",
     "lint:css-checkstyle": "stylelint \"**/*.css\" --custom-formatter ./node_modules/stylelint-checkstyle-formatter/index.js",
     "lint:yaml": "node ./node_modules/eslint/bin/eslint.js --ext .yml .",
-    "test:nightwatch": "node -r dotenv-safe/config ./node_modules/.bin/nightwatch --config ./tests/Drupal/Nightwatch/nightwatch.conf.js",
+    "test:nightwatch": "node -r dotenv-safe/config ./node_modules/.bin/nightwatch --config ./tests/Drupal/Nightwatch/nightwatch.conf.js --tag ckeditor5",
     "prettier": "prettier --write \"./**/*.js\"",
     "spellcheck": "cspell",
     "spellcheck:make-drupal-dict": "rm -f misc/cspell/dictionary.txt && touch misc/cspell/dictionary.txt && yarn -s spellcheck:core --unique --wordsOnly | tr '[:upper:]' '[:lower:]' | tr -d \\\\\\\\ | LC_ALL=C sort -u -o misc/cspell/dictionary.txt",