diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/data/db/AppDb.kt b/app/src/main/java/pl/szczodrzynski/edziennik/data/db/AppDb.kt
index aee8e3af..ff101fd0 100644
--- a/app/src/main/java/pl/szczodrzynski/edziennik/data/db/AppDb.kt
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/data/db/AppDb.kt
@@ -43,7 +43,7 @@ import pl.szczodrzynski.edziennik.data.db.migration.*
     LibrusLesson::class,
     TimetableManual::class,
     Metadata::class
-], version = 89)
+], version = 90)
 @TypeConverters(
         ConverterTime::class,
         ConverterDate::class,
@@ -174,7 +174,8 @@ abstract class AppDb : RoomDatabase() {
                 Migration86(),
                 Migration87(),
                 Migration88(),
-                Migration89()
+                Migration89(),
+                Migration90()
         ).allowMainThreadQueries().build()
     }
 }
diff --git a/app/src/main/java/pl/szczodrzynski/edziennik/data/db/migration/Migration90.kt b/app/src/main/java/pl/szczodrzynski/edziennik/data/db/migration/Migration90.kt
new file mode 100644
index 00000000..7b500525
--- /dev/null
+++ b/app/src/main/java/pl/szczodrzynski/edziennik/data/db/migration/Migration90.kt
@@ -0,0 +1,30 @@
+/*
+ * Copyright (c) Kuba Szczodrzyński 2021-2-26.
+ */
+
+package pl.szczodrzynski.edziennik.data.db.migration
+
+import androidx.room.migration.Migration
+import androidx.sqlite.db.SupportSQLiteDatabase
+
+class Migration90 : Migration(89, 90) {
+    override fun migrate(database: SupportSQLiteDatabase) {
+        // get all profiles using Vulcan/Hebe
+        database.execSQL("CREATE TABLE _90_ids (id INTEGER NOT NULL);")
+        database.execSQL("INSERT INTO _90_ids SELECT profileId FROM profiles JOIN loginStores USING(loginStoreId) WHERE loginStores.loginStoreType = 4 AND loginStores.loginStoreMode != 0;")
+
+        // force full sync when updating from <4.6
+        database.execSQL("DELETE FROM endpointTimers WHERE profileId IN (SELECT id FROM _90_ids);")
+        database.execSQL("UPDATE profiles SET empty = 1 WHERE profileId IN (SELECT id FROM _90_ids);")
+        // remove messages and events to re-download attachments and remove older than current school year
+        database.execSQL("DELETE FROM messages WHERE profileId IN (SELECT id FROM _90_ids);")
+        database.execSQL("DELETE FROM events WHERE profileId IN (SELECT id FROM _90_ids) AND eventAddedManually = 0;")
+        // remove older data
+        database.execSQL("DELETE FROM notices WHERE profileId IN (SELECT id FROM _90_ids);")
+
+        // fix for v4.5 users who logged in using Vulcan/Web
+        database.execSQL("UPDATE loginStores SET loginStoreMode = 2 WHERE loginStoreType = 4 AND loginStoreMode = 1;")
+
+        database.execSQL("DROP TABLE _90_ids;")
+    }
+}