diff --git a/src/python/gem5/components/boards/experimental/lupv_board.py b/src/python/gem5/components/boards/experimental/lupv_board.py
index 62ecfd59e4..326f944bf4 100644
--- a/src/python/gem5/components/boards/experimental/lupv_board.py
+++ b/src/python/gem5/components/boards/experimental/lupv_board.py
@@ -185,7 +185,9 @@ class LupvBoard(AbstractSystemBoard, KernelDiskWorkload):
         # point for our bbl to use upon startup, and will
         # remain unused during the simulation
         self.pic.n_src = 0
-        self.pic.hart_config = ""
+        self.pic.hart_config = ",".join(
+            ["M" for _ in range(self.processor.get_num_cores())]
+        )
         self.lupio_pic.n_src = max(pic_srcs) + 1
         self.lupio_pic.num_threads = self.processor.get_num_cores()