diff --git a/libs/database/src/main/java/org/fdroid/database/AppDao.kt b/libs/database/src/main/java/org/fdroid/database/AppDao.kt
index 0884b38e1..596d6ab30 100644
--- a/libs/database/src/main/java/org/fdroid/database/AppDao.kt
+++ b/libs/database/src/main/java/org/fdroid/database/AppDao.kt
@@ -684,7 +684,8 @@ internal interface AppDaoInt : AppDao {
     /**
      * Removes all apps and associated data such as versions from the database.
      * Careful: Doing this without other measures such as calling [RepositoryDaoInt.resetTimestamps]
-     * will cause application of diffs to fail.
+     * and [RepositoryDaoInt.resetETags] will cause things to break
+     * e.g. application of diffs to fail.
      */
     @Query("DELETE FROM ${AppMetadata.TABLE}")
     fun clearAll()
diff --git a/libs/database/src/main/java/org/fdroid/database/FDroidDatabase.kt b/libs/database/src/main/java/org/fdroid/database/FDroidDatabase.kt
index 146cc1583..4967f8f43 100644
--- a/libs/database/src/main/java/org/fdroid/database/FDroidDatabase.kt
+++ b/libs/database/src/main/java/org/fdroid/database/FDroidDatabase.kt
@@ -83,6 +83,7 @@ internal abstract class FDroidDatabaseInt : RoomDatabase(), FDroidDatabase, Clos
         runInTransaction {
             getAppDao().clearAll()
             getRepositoryDao().resetTimestamps()
+            getRepositoryDao().resetETags()
         }
     }
 }
diff --git a/libs/database/src/main/java/org/fdroid/database/RepositoryDao.kt b/libs/database/src/main/java/org/fdroid/database/RepositoryDao.kt
index 7ba36397a..816172f33 100644
--- a/libs/database/src/main/java/org/fdroid/database/RepositoryDao.kt
+++ b/libs/database/src/main/java/org/fdroid/database/RepositoryDao.kt
@@ -18,6 +18,7 @@ import org.fdroid.database.DbDiffUtils.diffAndUpdateListTable
 import org.fdroid.database.DbDiffUtils.diffAndUpdateTable
 import org.fdroid.index.IndexFormatVersion
 import org.fdroid.index.IndexParser.json
+import org.fdroid.index.v1.IndexV1Updater
 import org.fdroid.index.v2.IndexV2Updater
 import org.fdroid.index.v2.MirrorV2
 import org.fdroid.index.v2.ReflectionDiffer.applyDiff
@@ -420,7 +421,7 @@ internal interface RepositoryDaoInt : RepositoryDao {
         // move repoToReorder in place of repoTarget
         setWeight(repoToReorder.repoId, repoTarget.weight)
         // also adjust weight of archive repo, if it exists
-        val archiveRepoId = repoToReorder.certificate?.let { getArchiveRepoId(it) }
+        val archiveRepoId = getArchiveRepoId(repoToReorder.certificate)
         if (archiveRepoId != null) {
             setWeight(archiveRepoId, repoTarget.weight - 1)
         }
@@ -514,6 +515,13 @@ internal interface RepositoryDaoInt : RepositoryDao {
     @Query("UPDATE ${CoreRepository.TABLE} SET timestamp = -1")
     fun resetTimestamps()
 
+    /**
+     * Resets ETags for *all* repos in the database.
+     * This will use cause a full index update when updating the repository via [IndexV1Updater].
+     */
+    @Query("UPDATE ${RepositoryPreferences.TABLE} SET lastETag = NULL")
+    fun resetETags()
+
     /**
      * Use when replacing an existing repo with a full index.
      * This removes all existing index data associated with this repo from the database,