diff --git a/.claude/skills/recipe-upgrade/open-recipe-pr.sh b/.claude/skills/recipe-upgrade/open-recipe-pr.sh
index ab86dfa..e214573 100755
--- a/.claude/skills/recipe-upgrade/open-recipe-pr.sh
+++ b/.claude/skills/recipe-upgrade/open-recipe-pr.sh
@@ -102,6 +102,27 @@ if [ "${MODE}" != "--reconcile-only" ]; then
   DIVERGED=$(git log --oneline origin/main..HEAD 2>/dev/null || true)
   [ -n "${DIVERGED}" ] || { echo "ERROR: HEAD has no commits beyond origin/main. Nothing to PR."; exit 1; }
   LATEST_MSG=$(git log -1 --pretty=%s HEAD)
+
+  # --- Keep the LOCAL work current with the freshly-synced upstream main (anti-drift) ---
+  # The push path below grafts `HEAD^{tree}` WHOLESALE onto the PR branch. If this checkout is not
+  # based on the upstream main we just synced, every upstream change made since the branch was cut
+  # is silently ABSENT from the pushed tree — the PR (and the CI that verifies it) then describes a
+  # tree that will never deploy. Observed on gitea PR #5 (2026-08-10): its base predated upstream's
+  # "BREAKING CHANGE: remove forgejo", so `!testme` verified a forgejo-bearing tree while main had
+  # dropped it. Merge upstream in FIRST, and fail loudly rather than paper over a conflict.
+  if ! git merge-base --is-ancestor "${NEW_MAIN_SHA}" HEAD; then
+    echo "→ Local work predates upstream main (${NEW_MAIN_SHA:0:8}) — merging upstream in first..."
+    if ! GIT_AUTHOR_NAME="${GITEA_USERNAME}" GIT_AUTHOR_EMAIL="${GITEA_USERNAME}@git.autonomic.zone" \
+         GIT_COMMITTER_NAME="${GITEA_USERNAME}" GIT_COMMITTER_EMAIL="${GITEA_USERNAME}@git.autonomic.zone" \
+         git merge --no-edit "${NEW_MAIN_SHA}" >/dev/null 2>&1; then
+      git merge --abort 2>/dev/null || true
+      echo "ERROR: cannot auto-merge upstream main (${NEW_MAIN_SHA:0:8}) into the local ${RECIPE} work."
+      echo "       Upstream changed files this upgrade also touches. Resolve by hand in"
+      echo "       ${RECIPE_DIR}, then re-run. Refusing to push a tree that omits upstream changes."
+      exit 1
+    fi
+    echo "  ✓ upstream merged into the local work"
+  fi
 fi
 
 # --- Reconcile open PRs against the freshly-synced upstream main ---
@@ -165,9 +186,19 @@ if git rev-parse --verify --quiet "refs/remotes/gitea/${BRANCH}" >/dev/null; the
   if [ "$(git rev-parse 'HEAD^{tree}')" = "$(git rev-parse "${EXIST_TIP}^{tree}")" ]; then
     echo "→ '${BRANCH}' already has this exact tree — nothing new to push (will still re-test)."
   else
+    # Parent the new commit on the branch tip AND (when the branch predates it) on upstream main, so
+    # the recorded HISTORY matches the tree we are pushing. Without the second parent the merge-base
+    # stays stale: git would later treat upstream's post-branch changes as "removed by this PR" and a
+    # merge could revert them (the gitea #5 / forgejo-removal drift, 2026-08-10). No force-push: this
+    # is still a fast-forward from the branch tip.
+    EXTRA_PARENT=()
+    if ! git merge-base --is-ancestor "${NEW_MAIN_SHA}" "${EXIST_TIP}"; then
+      EXTRA_PARENT=(-p "${NEW_MAIN_SHA}")
+      echo "  (also parenting on upstream main ${NEW_MAIN_SHA:0:8} — branch predated it)"
+    fi
     ONTOP=$(GIT_AUTHOR_NAME="${GITEA_USERNAME}" GIT_AUTHOR_EMAIL="${GITEA_USERNAME}@git.autonomic.zone" \
             GIT_COMMITTER_NAME="${GITEA_USERNAME}" GIT_COMMITTER_EMAIL="${GITEA_USERNAME}@git.autonomic.zone" \
-            git commit-tree "$(git rev-parse 'HEAD^{tree}')" -p "${EXIST_TIP}" -m "${LATEST_MSG}")
+            git commit-tree "$(git rev-parse 'HEAD^{tree}')" -p "${EXIST_TIP}" "${EXTRA_PARENT[@]}" -m "${LATEST_MSG}")
     echo "→ Adding the new work on top of '${BRANCH}' (fast-forward, no force-push)..."
     git push gitea "${ONTOP}:refs/heads/${BRANCH}"
   fi