diff --git a/app/src/main/java/org/fdroid/fdroid/IndexV1Updater.java b/app/src/main/java/org/fdroid/fdroid/IndexV1Updater.java
index 187750581..73d4b8b53 100644
--- a/app/src/main/java/org/fdroid/fdroid/IndexV1Updater.java
+++ b/app/src/main/java/org/fdroid/fdroid/IndexV1Updater.java
@@ -24,7 +24,7 @@ package org.fdroid.fdroid;
 
 import android.content.ContentValues;
 import android.content.Context;
-
+import android.content.pm.PackageInfo;
 import androidx.annotation.NonNull;
 import android.text.TextUtils;
 import android.util.Log;
@@ -92,6 +92,8 @@ public class IndexV1Updater extends IndexUpdater {
     public static final String SIGNED_FILE_NAME = "index-v1.jar";
     public static final String DATA_FILE_NAME = "index-v1.json";
 
+    private static String platformSigCache;
+
     public IndexV1Updater(@NonNull Context context, @NonNull Repo repo) {
         super(context, repo);
     }
@@ -298,6 +300,11 @@ public class IndexV1Updater extends IndexUpdater {
         repo.maxage = getIntRepoValue(repoMap, "maxage");
         repo.version = getIntRepoValue(repoMap, "version");
 
+        if (TextUtils.isEmpty(platformSigCache)) {
+            PackageInfo androidPackageInfo = Utils.getPackageInfoWithSignatures(context, "android");
+            platformSigCache = Utils.getPackageSig(androidPackageInfo);
+        }
+
         RepoPersister repoPersister = new RepoPersister(context, repo);
         if (apps != null && apps.length > 0) {
             int appCount = 0;
@@ -319,6 +326,8 @@ public class IndexV1Updater extends IndexUpdater {
                     for (Apk apk : apks) {
                         if (!apk.isApk()) {
                             app.isApk = false;
+                        } else if (apk.sig.equals(platformSigCache)) {
+                            app.preferredSigner = platformSigCache;
                         }
                     }
                 }
diff --git a/app/src/main/java/org/fdroid/fdroid/Utils.java b/app/src/main/java/org/fdroid/fdroid/Utils.java
index 957746579..b9b101d48 100644
--- a/app/src/main/java/org/fdroid/fdroid/Utils.java
+++ b/app/src/main/java/org/fdroid/fdroid/Utils.java
@@ -19,6 +19,7 @@
 
 package org.fdroid.fdroid;
 
+import android.annotation.SuppressLint;
 import android.content.Context;
 import android.content.pm.PackageInfo;
 import android.content.pm.PackageManager;
@@ -808,6 +809,21 @@ public final class Utils {
         return null;
     }
 
+    /**
+     * Try to get the {@link PackageInfo} with signature info for the {@code packageName} provided.
+     *
+     * @return null on failure
+     */
+    @SuppressLint("PackageManagerGetSignatures")
+    public static PackageInfo getPackageInfoWithSignatures(Context context, String packageName) {
+        try {
+            return context.getPackageManager().getPackageInfo(packageName, PackageManager.GET_SIGNATURES);
+        } catch (PackageManager.NameNotFoundException e) {
+            debugLog(TAG, "Could not get PackageInfo: ", e);
+        }
+        return null;
+    }
+
     /**
      * Useful for debugging during development, so that arbitrary queries can be made, and their
      * results inspected in the debugger.