diff --git a/.github/workflows/flutter-build.yml b/.github/workflows/flutter-build.yml
index c06626414..a5dedd8d9 100644
--- a/.github/workflows/flutter-build.yml
+++ b/.github/workflows/flutter-build.yml
@@ -403,7 +403,10 @@ jobs:
         if: env.MACOS_P12_BASE64 != null
         run: |
           # Patch create-dmg to give more attempts to unmount image
-          sed -i -e 's/MAXIMUM_UNMOUNTING_ATTEMPTS=3/MAXIMUM_UNMOUNTING_ATTEMPTS=7/' $(command -v create-dmg)
+          CREATE_DMG="$(command -v create-dmg)"
+          CREATE_DMG="$(readlink -f "$CREATE_DMG")"
+          sed -i -e 's/MAXIMUM_UNMOUNTING_ATTEMPTS=3/MAXIMUM_UNMOUNTING_ATTEMPTS=7/' "$CREATE_DMG"
+          # Unlock keychain
           security default-keychain -s rustdesk.keychain
           security unlock-keychain -p ${{ secrets.MACOS_P12_PASSWORD }} rustdesk.keychain
           # start sign the rustdesk.app and dmg