diff --git a/.github/workflows/build-postgres.yaml b/.github/workflows/build-postgres.yaml
index 1825ed8..8debbd9 100644
--- a/.github/workflows/build-postgres.yaml
+++ b/.github/workflows/build-postgres.yaml
@@ -6,7 +6,7 @@ on:
       tag:
         description: "postgres tag to build in the format REL_<MAJOR>_<MINOR>"
         required: true
-        default: REL_16_5 # DO NOT CHANGE THIS LINE. this default value will be overridden automatically
+        default: REL_15_9 # DO NOT CHANGE THIS LINE. this default value will be overridden automatically
   workflow_call:
     inputs:
       tag:
diff --git a/.github/workflows/on-push.yaml b/.github/workflows/on-push.yaml
index 15a4847..f9f6dcf 100644
--- a/.github/workflows/on-push.yaml
+++ b/.github/workflows/on-push.yaml
@@ -8,4 +8,4 @@ jobs:
   call-build:
     uses: ./.github/workflows/build-postgres.yaml
     with:
-      tag: REL_16_5 # DO NOT CHANGE THIS LINE. this default value will be overridden automatically
+      tag: REL_15_9 # DO NOT CHANGE THIS LINE. this default value will be overridden automatically