diff --git a/app/build.gradle b/app/build.gradle
index 4966d9f0..eb57cb92 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -80,6 +80,7 @@ dependencies {
     implementation 'eu.davidea:flexible-adapter-ui:1.0.0-b1'
     implementation 'org.apache.commons:commons-collections4:4.1'
     implementation 'org.greenrobot:greendao:3.2.2'
+    implementation 'com.github.yuweiguocn:GreenDaoUpgradeHelper:v2.0.2'
     implementation 'com.jakewharton:butterknife:8.8.1'
     implementation 'joda-time:joda-time:2.9.9'
     implementation 'com.google.dagger:dagger-android:2.14.1'
diff --git a/app/src/main/java/io/github/wulkanowy/data/db/dao/DbHelper.java b/app/src/main/java/io/github/wulkanowy/data/db/dao/DbHelper.java
index 9392bae5..a67e9b7f 100644
--- a/app/src/main/java/io/github/wulkanowy/data/db/dao/DbHelper.java
+++ b/app/src/main/java/io/github/wulkanowy/data/db/dao/DbHelper.java
@@ -3,20 +3,26 @@ package io.github.wulkanowy.data.db.dao;
 import android.content.Context;
 import android.database.sqlite.SQLiteDatabase;
 
+import com.github.yuweiguocn.library.greendao.MigrationHelper;
+
 import org.greenrobot.greendao.database.Database;
 import org.greenrobot.greendao.database.StandardDatabase;
 
 import javax.inject.Inject;
 import javax.inject.Singleton;
 
+import io.github.wulkanowy.BuildConfig;
+import io.github.wulkanowy.data.db.dao.entities.AccountDao;
 import io.github.wulkanowy.data.db.dao.entities.DaoMaster;
+import io.github.wulkanowy.data.db.dao.entities.GradeDao;
+import io.github.wulkanowy.data.db.dao.entities.SubjectDao;
 import io.github.wulkanowy.data.db.shared.SharedPrefContract;
 import io.github.wulkanowy.di.annotations.ApplicationContext;
 import io.github.wulkanowy.di.annotations.DatabaseInfo;
 import io.github.wulkanowy.utils.LogUtils;
 
 @Singleton
-public class DbHelper extends DaoMaster.DevOpenHelper {
+public class DbHelper extends DaoMaster.OpenHelper {
 
     private SharedPrefContract sharedPref;
 
@@ -28,19 +34,28 @@ public class DbHelper extends DaoMaster.DevOpenHelper {
     }
 
     @Override
+    @SuppressWarnings("unchecked")
     public void onUpgrade(Database db, int oldVersion, int newVersion) {
-        cleanUserData(db, oldVersion, newVersion);
+        MigrationHelper.DEBUG = BuildConfig.DEBUG;
+        MigrationHelper.migrate(db, new MigrationHelper.ReCreateAllTableListener() {
+            @Override
+            public void onCreateAllTables(Database db, boolean ifNotExists) {
+                DaoMaster.createAllTables(db, ifNotExists);
+            }
+            @Override
+            public void onDropAllTables(Database db, boolean ifExists) {
+                DaoMaster.dropAllTables(db, ifExists);
+            }
+        }, AccountDao.class, SubjectDao.class, GradeDao.class);
     }
 
     @Override
     public void onDowngrade(SQLiteDatabase db, int oldVersion, int newVersion) {
-        cleanUserData(new StandardDatabase(db), oldVersion, newVersion);
-    }
-
-    private void cleanUserData(Database database, int oldVersion, int newVersion) {
-        LogUtils.info("Cleaning user data oldVersion=" + oldVersion + " newVersion=" + newVersion);
+        Database database = new StandardDatabase(db);
         DaoMaster.dropAllTables(database, true);
         onCreate(database);
         sharedPref.setCurrentUserId(0);
+
+        LogUtils.info("Cleaning user data oldVersion=" + oldVersion + " newVersion=" + newVersion);
     }
 }
diff --git a/app/src/main/java/io/github/wulkanowy/ui/main/attendance/AttendanceHeaderItem.java b/app/src/main/java/io/github/wulkanowy/ui/main/attendance/AttendanceHeaderItem.java
index 0270f7c1..b103a007 100644
--- a/app/src/main/java/io/github/wulkanowy/ui/main/attendance/AttendanceHeaderItem.java
+++ b/app/src/main/java/io/github/wulkanowy/ui/main/attendance/AttendanceHeaderItem.java
@@ -18,7 +18,6 @@ import eu.davidea.flexibleadapter.FlexibleAdapter;
 import eu.davidea.flexibleadapter.items.AbstractExpandableHeaderItem;
 import eu.davidea.viewholders.ExpandableViewHolder;
 import io.github.wulkanowy.R;
-import io.github.wulkanowy.data.db.dao.entities.AttendanceLesson;
 import io.github.wulkanowy.data.db.dao.entities.Day;
 
 public class AttendanceHeaderItem
diff --git a/build.gradle b/build.gradle
index 13b22854..999f91de 100644
--- a/build.gradle
+++ b/build.gradle
@@ -36,6 +36,7 @@ allprojects {
         jcenter()
         mavenCentral()
         google()
+        maven { url "https://jitpack.io" }
     }
 }