diff --git a/scripts/host_tool_runner.sh b/scripts/host_tool_runner.sh
index 6ae003a3..09be2394 100755
--- a/scripts/host_tool_runner.sh
+++ b/scripts/host_tool_runner.sh
@@ -258,6 +258,7 @@ sync_host_generated_headers() {
 
   (
     cd "${WORK_DIR}"
+    mkdir -p cereal/gen/cpp
     capnpc --src-prefix=cereal \
       cereal/log.capnp \
       cereal/car.capnp \