diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 9386b9f43d09d63605c4149b8011915230af7ea4..d733c0faa35e39679ca3beebabc1bdbb935443a5 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -21,10 +21,12 @@ jobs:
     runs-on: self-hosted
     strategy:
       matrix:
-        # LCG_RELEASE: [LCG_EXTERNAL, KEY4HEP_STACK]
-        LCG_RELEASE: [LCG_EXTERNAL]
-        # CEPCSW_BLDTOOL: [make, ninja]
-        CEPCSW_BLDTOOL: [ninja]
+        LCG_RELEASE: 
+          - LCG_EXTERNAL
+          - KEY4HEP_STACK
+        CEPCSW_BLDTOOL:
+          - ninja
+        # - make
 
     # Steps represent a sequence of tasks that will be executed as part of the job
     steps: