diff --git a/metadata/de.nucleus.foss_warn.yml b/metadata/de.nucleus.foss_warn.yml
index 0bb68366c7..4c37298111 100644
--- a/metadata/de.nucleus.foss_warn.yml
+++ b/metadata/de.nucleus.foss_warn.yml
@@ -86,7 +86,7 @@ Builds:
       - flutter@2.8.1
     rm:
       - ios
-    prebuild: sed -i -e '/useProguard/,/proguardFiles/d' android/app/build.gradle
+      - android/app/proguard-rules.pro
     build:
       - $$flutter$$/bin/flutter config --no-analytics
       - $$flutter$$/bin/flutter build apk --release --verbose