diff --git a/selfdrive/test/scons_build_test.sh b/selfdrive/test/scons_build_test.sh
index efc9469deb..8048d3acb7 100755
--- a/selfdrive/test/scons_build_test.sh
+++ b/selfdrive/test/scons_build_test.sh
@@ -1,4 +1,5 @@
 #!/usr/bin/env bash
+set -e
 
 SCRIPT_DIR=$(dirname "$0")
 BASEDIR=$(realpath "$SCRIPT_DIR/../../")
@@ -6,5 +7,11 @@ cd $BASEDIR
 
 # tests that our build system's dependencies are configured properly,
 # needs a machine with lots of cores
+
+cd $BASEDIR/opendbc_repo/
 scons --clean
 scons --no-cache --random -j$(nproc)
+if ! scons -q; then
+  echo "FAILED: all build products not up to date after first pass."
+  exit 1
+fi