diff --git a/local/scripts/check-fork-drift.sh b/local/scripts/check-fork-drift.sh
index 9c6f9366cc..7db65a032e 100755
--- a/local/scripts/check-fork-drift.sh
+++ b/local/scripts/check-fork-drift.sh
@@ -78,6 +78,12 @@ for fork in "${FORKS[@]}"; do
         continue
     fi
 
+    # Respect diverged mode from fork-upstream-map.toml — these forks are
+    # intentionally ahead of upstream with RB-specific work. Drift is expected.
+    if grep -q "^${fork}[[:space:]]\+.*diverged" "$PROJECT_ROOT/local/fork-upstream-map.toml" 2>/dev/null; then
+        continue
+    fi
+
     # Determine upstream branch (master or main)
     upstream_branch="master"
     if ! (cd "$fork_dir" && git rev-parse --verify upstream/master >/dev/null 2>&1); then