diff --git a/Tools/scripts/sitl-on-hardware/sitl-on-hw.py b/Tools/scripts/sitl-on-hardware/sitl-on-hw.py
index 112f67f49eb..b71ec6cdb6f 100755
--- a/Tools/scripts/sitl-on-hardware/sitl-on-hw.py
+++ b/Tools/scripts/sitl-on-hardware/sitl-on-hw.py
@@ -102,7 +102,8 @@ hwdef_write(open(sohw_path(extra_hwdef_base), "r").read() + "\n")
 defaults_write(open(sohw_path(defaults_base), "r").read() + "\n")
 
 if args.defaults:
-    defaults_write(open(args.defaults, "r").read() + "\n")
+    for d in args.defaults.split(","):
+        defaults_write(open(d, "r").read() + "\n")
 
 if args.simclass:
     if args.simclass == 'Glider':