diff --git a/core/.build-builder b/core/.build-builder
new file mode 100644
index 0000000000..faf4c870a9
--- /dev/null
+++ b/core/.build-builder
@@ -0,0 +1,4 @@
+The presence of this file tells CI to use the new builder_ style parameters for build.sh.
+
+Once all branches for 16.0+ are updated to merge the chore/core/7247-use-builder-for-build-sh branch, then we
+can remove this file and the corresponding bash test branches in CI.