diff --git a/images/opentelemetry/cloudbuild.yaml b/images/opentelemetry/cloudbuild.yaml
index d507b8f1a..5a4e1b3c0 100644
--- a/images/opentelemetry/cloudbuild.yaml
+++ b/images/opentelemetry/cloudbuild.yaml
@@ -21,4 +21,4 @@ steps:
       && make push
 substitutions:
   _GIT_TAG: "12345"
-  _PULL_BASE_REF: "master"
+  _PULL_BASE_REF: "main"