diff --git a/.drone.yml b/.drone.yml
index 5865e2a52e0..849721a8def 100644
--- a/.drone.yml
+++ b/.drone.yml
@@ -5,7 +5,7 @@ steps:
     image: nextcloudci/php7.3:php7.3-5
     environment:
       APP_NAME: text
-      CORE_BRANCH: master
+      CORE_BRANCH: stable21
       DB: sqlite
     commands:
       - composer install
@@ -28,7 +28,7 @@ steps:
     image: nextcloudci/php7.3:php7.3-5
     environment:
       APP_NAME: text
-      CORE_BRANCH: master
+      CORE_BRANCH: stable21
       DB: sqlite
     commands:
       - bash ./tests/drone-server-setup.sh $APP_NAME $CORE_BRANCH $DB
@@ -61,7 +61,7 @@ steps:
     image: nextcloudci/php7.3:php7.3-5
     environment:
       APP_NAME: text
-      CORE_BRANCH: master
+      CORE_BRANCH: stable21
       DB: mysql
     commands:
       - bash ./tests/drone-server-setup.sh $APP_NAME $CORE_BRANCH $DB
@@ -92,7 +92,7 @@ steps:
     image: nextcloudci/php7.3:php7.3-5
     environment:
       APP_NAME: text
-      CORE_BRANCH: master
+      CORE_BRANCH: stable21
       DB: postgres
     commands:
       - bash ./tests/drone-server-setup.sh $APP_NAME $CORE_BRANCH $DB
diff --git a/.github/workflows/oci.yml b/.github/workflows/oci.yml
index 18a75d9c0dc..5462828eb0d 100644
--- a/.github/workflows/oci.yml
+++ b/.github/workflows/oci.yml
@@ -24,7 +24,7 @@ jobs:
       matrix:
         php-versions: ['7.4']
         databases: ['oci']
-        server-versions: ['master']
+        server-versions: ['stable21']
 
     name: php${{ matrix.php-versions }}-${{ matrix.databases }}-${{ matrix.server-versions }}