diff --git a/packaging/macos/dmg/README.md b/packaging/macos/dmg/README.md
index ec902e30f..460f7bdeb 100644
--- a/packaging/macos/dmg/README.md
+++ b/packaging/macos/dmg/README.md
@@ -2,8 +2,8 @@
 
 What Finder shows when the DMG opens: a 660 × 400 pt background with the app icon and the
 `Applications` link side by side. `package.sh` copies these files into the image; nothing here is
-generated at build time, so the DMG still builds with `hdiutil makehybrid` (no mounted device, no
-Finder scripting on CI, nothing extra installed in the signing job).
+generated at build time, so the DMG builds with a plain `hdiutil create -srcfolder` (no Finder
+scripting on CI, nothing extra installed in the signing job).
 
 | File | What |
 |---|---|
diff --git a/packaging/macos/package.sh b/packaging/macos/package.sh
index c73581a24..e04be13c8 100755
--- a/packaging/macos/package.sh
+++ b/packaging/macos/package.sh
@@ -137,15 +137,40 @@ ln -s /Applications "$STAGE/Applications"
 mkdir -p "$STAGE/.background"
 cp "$HERE/dmg/background.tiff" "$STAGE/.background/background.tiff"
 cp "$HERE/dmg/dmg-layout.DS_Store" "$STAGE/.DS_Store"
-rm -f "$DMG" "$WORK/raw.dmg"
-# makehybrid + convert builds the image without attaching a device, unlike `create -srcfolder`,
-# which is flaky on CI runners ("Resource busy") and hangs in sandboxed sessions.
-# The volume name has no version: .DS_Store finds the background through an alias that includes it.
-hdiutil makehybrid -hfs -hfs-volume-name "PdfCraft" -hfs-openfolder "$STAGE" -o "$WORK/raw.dmg" "$STAGE"
-hdiutil convert "$WORK/raw.dmg" -format UDZO -imagekey zlib-level=9 -o "$DMG"
-rm -f "$WORK/raw.dmg"
+rm -f "$DMG"
+# `hdiutil create -srcfolder` writes the files as they are. `makehybrid -hfs` gave every file a
+# com.apple.FinderInfo (a Finder location of -1,-1), which `codesign --verify --strict` rejects as
+# "Finder information, or similar detritus" on the app in the image and on a copy installed from it,
+# so MDM and compliance checks reported a correctly notarized app as damaged (#390). `create`
+# attaches a device while it copies, which fails now and then on CI runners ("Resource busy"), so
+# it gets a few tries. The volume name has no version: .DS_Store finds the background through an
+# alias that includes it.
+# Usage: hdiutil_retry <what> <hdiutil args…>; tries five times with growing pauses.
+hdiutil_retry() {
+  local what="$1" attempt
+  shift
+  for attempt in 1 2 3 4 5; do
+    if hdiutil "$@"; then
+      return 0
+    fi
+    [ "$attempt" = 5 ] && { echo "hdiutil $what failed 5 times" >&2; return 1; }
+    warn "hdiutil $what failed (attempt $attempt of 5); retrying in $((attempt * 10))s"
+    sleep $((attempt * 10))
+  done
+}
+hdiutil_retry create create -srcfolder "$STAGE" -volname "PdfCraft" -fs HFS+ -format UDZO -imagekey zlib-level=9 -ov "$DMG"
 sign "$DMG"
 codesign --verify --strict --verbose=2 "$DMG"
+# The app inside the image must still pass --strict, so a makehybrid-style regression can't ship.
+MOUNT="$WORK/dmg-check"
+rm -rf "$MOUNT"
+mkdir -p "$MOUNT"
+hdiutil_retry attach attach -nobrowse -readonly -mountpoint "$MOUNT" "$DMG" >/dev/null
+if ! codesign --verify --strict --deep --verbose=2 "$MOUNT/PdfCraft.app"; then
+  hdiutil_retry detach detach "$MOUNT" >/dev/null || true
+  exit 1
+fi
+hdiutil_retry detach detach "$MOUNT" >/dev/null
 if [ "$NOTARIZE" = 1 ]; then
   notarize "$DMG"
   xcrun stapler staple "$DMG"