diff --git a/.github/workflows/gpu-ci.yml b/.github/workflows/gpu-ci.yml
index 1863939..a35815e 100644
--- a/.github/workflows/gpu-ci.yml
+++ b/.github/workflows/gpu-ci.yml
@@ -25,6 +25,15 @@ jobs:
     if: contains(github.event.pull_request.labels.*.name, 'needs-gpu-ci')
     runs-on: ubuntu-latest
     timeout-minutes: 60
+
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - { gpu_id: "NVIDIA RTX A4000",      target_sm: "8.6" }   # SM86
+          - { gpu_id: "NVIDIA A100 80GB PCIe", target_sm: "8.0" }   # SM80
+          - { gpu_id: "NVIDIA H100 80GB HBM3", target_sm: "9.0", force_sm90: "1" }  # SM90
+
     steps:
       - name: Checkout secure orchestrator script from base branch
         uses: actions/checkout@v4
@@ -67,7 +76,7 @@ jobs:
           RUNPOD_API_KEY: ${{ secrets.RUNPOD_API_KEY }}
           PR_REPO_URL: ${{ github.event.pull_request.head.repo.clone_url }}
           PR_SHA: ${{ github.event.pull_request.head.sha }}
-          # GPU_ID: ${{ matrix.gpu_id }}
-          # TARGET_SM: ${{ matrix.target_sm }}
-          # KERNEL_ALIGN_FORCE_SM90: ${{ matrix.force_sm90 }}
+          GPU_ID: ${{ matrix.gpu_id }}
+          TARGET_SM: ${{ matrix.target_sm }}
+          KERNEL_ALIGN_FORCE_SM90: ${{ matrix.force_sm90 }}
         run: bash ci/run_gpu_ci.sh
diff --git a/envs.py b/envs.py
index abd12b1..34aded7 100644
--- a/envs.py
+++ b/envs.py
@@ -12,7 +12,7 @@
 
 def env_flag(name: str, default: bool = False) -> bool:
     value = os.environ.get(name)
-    if value is None:
+    if not value or value.strip() == "":
         return default
     normalized = value.strip().lower()
     if normalized in {"1", "true", "yes", "on"}: