diff --git a/make/test_build_system.sh b/make/test_build_system.sh
index 5be1504e3d..86be1f82ec 100755
--- a/make/test_build_system.sh
+++ b/make/test_build_system.sh
@@ -80,6 +80,13 @@ function run_tests()
 		 failure "Files weren't cleaned: ${ALL_BUILD_FILES}"
 	fi
 
+    print_status "Bootloader build shouldn't leave build output anywhere else"
+    rm -rf --preserve-root ${BUILD}
+    make bootloader
+    # find wizardry: find any file not named sdkconfig.h that
+    # isn't in the "bootloader" or "config" directories
+    find ${BUILD} -type d \( -name bootloader -o -name config \) -prune , -type f ! -name sdkconfig.h || failure "Bootloader built files outside the bootloader or config directories"
+
 	print_status "Can still clean build if all text files are CRLFs"
 	make clean
 	find . -exec unix2dos {} \; # CRLFify template dir