diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index ae750499..328cf420 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -13,9 +13,11 @@ on:
 
 env:
   FORCE_JAVASCRIPT_ACTIONS_TO_NODE24: "true"
-  # Required CI records pytest-testmon data but still runs the full selected suite.
-  # The selective mode stays on explicit developer flows such as `just testmon`.
-  BASIC_MEMORY_TESTMON_FLAGS: "--testmon-noselect"
+  # PR builds select only tests impacted by the change, using the cached
+  # testmon baseline (branch cache falling back to main's full-run recording) —
+  # same policy as basic-memory-cloud. Pushes to main run the full suite with
+  # --testmon-noselect, which refreshes the baseline the PR builds select from.
+  BASIC_MEMORY_TESTMON_FLAGS: ${{ github.event_name == 'pull_request' && '--testmon --testmon-forceselect' || '--testmon-noselect' }}
 
 jobs:
   static-checks: