diff --git a/infra/k8s/argo/alpha-rl-template.yaml b/infra/k8s/argo/alpha-rl-template.yaml
index 5a00bfcc4..81d9d4b44 100644
--- a/infra/k8s/argo/alpha-rl-template.yaml
+++ b/infra/k8s/argo/alpha-rl-template.yaml
@@ -158,6 +158,7 @@ spec:
 
             # Auto-detect GPU compute capability for all crates' build.rs
             export CUDA_COMPUTE_CAP=$(nvidia-smi --query-gpu=compute_cap --format=csv,noheader | head -1 | tr -d '.')
+            export FOXHUNT_CUDA_ARCH="sm_${CUDA_COMPUTE_CAP}"
             echo "=== GPU arch: sm_${CUDA_COMPUTE_CAP} ==="
 
             # Clear stale build artifacts when arch changes