diff --git a/.gitignore b/.gitignore
index 79ed325..247457f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,3 +2,4 @@ build/
 sdkconfig
 sdkconfig.old
 managed_components/
+build-*/
diff --git a/sdkconfig.selftest_fail b/sdkconfig.selftest_fail
new file mode 100644
index 0000000..c2ec820
--- /dev/null
+++ b/sdkconfig.selftest_fail
@@ -0,0 +1,4 @@
+# Rollback test build only (step 2b). Build in its own directory, e.g.:
+#   idf.py -B build-selftest-fail -DSDKCONFIG=build-selftest-fail/sdkconfig \
+#          -DSDKCONFIG_DEFAULTS="sdkconfig.defaults;sdkconfig.selftest_fail" build
+CONFIG_AES67_OTA_SELFTEST_FORCE_FAIL=y