diff --git a/python/test/unit/runtime/test_comm.py b/python/test/unit/runtime/test_comm.py
index ae843a15f..520462870 100644
--- a/python/test/unit/runtime/test_comm.py
+++ b/python/test/unit/runtime/test_comm.py
@@ -23,13 +23,13 @@ def get_p2p_matrix():
 def get_p2p_devices():
     matrix = get_p2p_matrix()
     idx = np.where(matrix == "OK")
-    return f"cuda:{idx[0][0]}", f"cuda:{idx[1][0]}"
+    return [f"cuda:{idx[0][0]}", f"cuda:{idx[1][0]}"] if len(idx[0]) > 0 else []
 
 
 def get_non_p2p_devices():
     matrix = get_p2p_matrix()
     idx = np.where(matrix == "NS")
-    return f"cuda:{idx[0][0]}", f"cuda:{idx[1][0]}"
+    return [f"cuda:{idx[0][0]}", f"cuda:{idx[1][0]}"] if len(idx[0]) > 0 else []
 
 
 p2p_devices = get_p2p_devices()