diff --git a/docs/platforms/mac/release.md b/docs/platforms/mac/release.md
index 800f0164a86..31ee7819a82 100644
--- a/docs/platforms/mac/release.md
+++ b/docs/platforms/mac/release.md
@@ -27,7 +27,7 @@ This app now ships Sparkle auto-updates. Release builds must be Developer ID–s
 Notes:
 
 - `APP_BUILD` maps to `CFBundleVersion`/`sparkle:version`; keep it numeric + monotonic (no `-beta`), or Sparkle compares it as equal.
-- If `APP_BUILD` is omitted, `scripts/package-mac-app.sh` derives a Sparkle-safe default from `APP_VERSION` (`YYYYMMDD0`) and uses the higher of that value and git commit count.
+- If `APP_BUILD` is omitted, `scripts/package-mac-app.sh` derives a Sparkle-safe default from `APP_VERSION` (`YYYYMMDDNN`: stable defaults to `90`, prereleases use a suffix-derived lane) and uses the higher of that value and git commit count.
 - You can still override `APP_BUILD` explicitly when release engineering needs a specific monotonic value.
 - Defaults to the current architecture (`$(uname -m)`). For release/universal builds, set `BUILD_ARCHS="arm64 x86_64"` (or `BUILD_ARCHS=all`).
 - Use `scripts/package-mac-dist.sh` for release artifacts (zip + DMG + notarization). Use `scripts/package-mac-app.sh` for local/dev packaging.
diff --git a/scripts/package-mac-app.sh b/scripts/package-mac-app.sh
index 4ed4e258829..021eb85e4c1 100755
--- a/scripts/package-mac-app.sh
+++ b/scripts/package-mac-app.sh
@@ -35,7 +35,20 @@ canonical_build_from_version() {
     local year="${BASH_REMATCH[1]}"
     local month="${BASH_REMATCH[2]}"
     local day="${BASH_REMATCH[3]}"
-    printf "%d%02d%02d0" "$year" "$month" "$day"
+    local suffix="${BASH_REMATCH[4]:-}"
+    local lane=90
+    # Keep stable releases above same-day prereleases so Sparkle can advance beta -> stable.
+    if [[ -n "$suffix" ]]; then
+      if [[ "$suffix" =~ ([0-9]+)$ ]]; then
+        lane=$((10#${BASH_REMATCH[1]}))
+        if (( lane > 89 )); then
+          lane=89
+        fi
+      else
+        lane=1
+      fi
+    fi
+    printf "%d%02d%02d%02d" "$year" "$month" "$day" "$lane"
     return 0
   fi
   return 1