diff --git a/sunnypilot/modeld/SConscript b/sunnypilot/modeld/SConscript
index 3a1ab56848..87ca756a86 100644
--- a/sunnypilot/modeld/SConscript
+++ b/sunnypilot/modeld/SConscript
@@ -62,10 +62,10 @@ lenv.Command(fn + "_metadata.pkl", [fn + ".onnx"] + tinygrad_files, cmd)
 # Build thneed model
 pythonpath_string = 'PYTHONPATH="${PYTHONPATH}:' + env.Dir("#sunnypilot/tinygrad_repo").abspath + '"'
 if arch == "larch64" or GetOption('pc_thneed'):
-  tinygrad_opts = []
+  tinygrad_opts = ''
   if not GetOption('pc_thneed'):
     # use FLOAT16 on device for speed + don't cache the CL kernels for space
-    tinygrad_opts += ["FLOAT16=1", "PYOPENCL_NO_CACHE=1"]
+    tinygrad_opts = 'FLOAT16=1 PYOPENCL_NO_CACHE=1'
   cmd = f'{pythonpath_string} {tinygrad_opts} python3 {Dir("#sunnypilot/tinygrad_repo").abspath}/openpilot/compile2.py {fn}.onnx {fn}.thneed'
 
   lenv.Command(fn + ".thneed", [fn + ".onnx"] + tinygrad_files, cmd)