diff --git a/firmware/fw_base.S b/firmware/fw_base.S
index b28cfb5..ae14cc7 100644
--- a/firmware/fw_base.S
+++ b/firmware/fw_base.S
@@ -114,6 +114,7 @@ _fdt_reloc_done:
 
 	/* Wait for boot hart */
 _wait_for_boot_hart:
+	fence	rw, rw
 	la	a4, _boot_hart_done
 	REG_L	a5, (a4)
 	beqz	a5, _wait_for_boot_hart