diff --git a/includes/include.drupalci.main.yml b/includes/include.drupalci.main.yml
index a45eb8d..6096ed2 100644
--- a/includes/include.drupalci.main.yml
+++ b/includes/include.drupalci.main.yml
@@ -249,6 +249,8 @@ stages:
     # For Nightwatch et al.
     - yarn --cwd $_WEB_ROOT/core install
     - touch $_WEB_ROOT/core/.env
+    # Display any deprecation warning which may have been set.
+    - printf "$_DEPRECATION_MESSAGE"

 composer:
   extends: .composer-base
@@ -681,9 +683,11 @@ phpunit (next major):
 .simpletest_db:
   - printf "**********\n* Out of date reference .simpletest_db is used.\n* To remove this warning, replace it with .simpletest-db\n**********\n"
   - *simpletest-db
+
+# Cater for deprecation of .skip-composer-rule and $SKIP_COMPOSER variable.
 .skip-composer-rule:
-  if: $OPT_IN_TEST_CURRENT == "0" || $SKIP_COMPOSER == "1"
-  when: never
+  variables:
+    _DEPRECATION_MESSAGE: "**********\n* The .skip-composer-rule is deprecated in version 1.1.0 and reference to this rule should be deleted.\n* See https://www.drupal.org/project/gitlab_templates/issues/3414391\n**********\n"

 deprecation warning:
   stage: .pre