diff --git a/.github/workflows/CI-advanced.yml b/.github/workflows/CI-advanced.yml
index 26deddf..30026b4 100644
--- a/.github/workflows/CI-advanced.yml
+++ b/.github/workflows/CI-advanced.yml
@@ -26,6 +26,8 @@ jobs:
       matrix:
         gap-branch:
           - master
+          - stable-4.15
+          - stable-4.14
           - stable-4.13
           - stable-4.12
           - stable-4.11
diff --git a/.github/workflows/CI.yml b/.github/workflows/CI.yml
index 150fd6d..4fa116f 100644
--- a/.github/workflows/CI.yml
+++ b/.github/workflows/CI.yml
@@ -26,6 +26,7 @@ jobs:
       matrix:
         gap-branch:
           - master
+          - stable-4.15
           - stable-4.14
           - stable-4.13
           - stable-4.12