diff --git a/scripts/performance/run_script.py b/scripts/performance/run_script.py
index f5df41fc3e..2787f8c6f3 100644
--- a/scripts/performance/run_script.py
+++ b/scripts/performance/run_script.py
@@ -95,6 +95,11 @@ def main():
         config_variant=args.config_variant,
     )
 
+    # Set NCCL env vars for nccl_ub enabled via recipe config (not just CLI).
+    if getattr(recipe.ddp, "nccl_ub", False):
+        os.environ.setdefault("NCCL_NVLS_ENABLE", "1")
+        os.environ.setdefault("NCCL_CTA_POLICY", "1")
+
     # Select forward step function based on the model family name.
     if args.domain == "vlm":
         forward_step_func = vlm_forward_step