diff --git a/matrix-sdk-android/proguard-rules.pro b/matrix-sdk-android/proguard-rules.pro
index 08a20cbf0a..fa860d8049 100644
--- a/matrix-sdk-android/proguard-rules.pro
+++ b/matrix-sdk-android/proguard-rules.pro
@@ -64,3 +64,19 @@
 
 ### Webrtc
 -keep class org.webrtc.** { *; }
+
+### Serializable persisted classes
+# https://www.guardsquare.com/en/products/proguard/manual/examples#serializable
+-keepnames class * implements java.io.Serializable
+
+-keepclassmembers class * implements java.io.Serializable {
+    static final long serialVersionUID;
+    private static final java.io.ObjectStreamField[] serialPersistentFields;
+    !static !transient <fields>;
+    !private <fields>;
+    !private <methods>;
+    private void writeObject(java.io.ObjectOutputStream);
+    private void readObject(java.io.ObjectInputStream);
+    java.lang.Object writeReplace();
+    java.lang.Object readResolve();
+}
\ No newline at end of file
diff --git a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/store/db/RealmCryptoStoreMigration.kt b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/store/db/RealmCryptoStoreMigration.kt
index eb2fc9ebad..47af558b90 100644
--- a/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/store/db/RealmCryptoStoreMigration.kt
+++ b/matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/crypto/store/db/RealmCryptoStoreMigration.kt
@@ -182,7 +182,8 @@ internal class RealmCryptoStoreMigration @Inject constructor(private val crossSi
                     try {
                         val oldSerializedData = obj.getString("olmInboundGroupSessionData")
                         deserializeFromRealm<MXOlmInboundGroupSession2>(oldSerializedData)?.let { mxOlmInboundGroupSession2 ->
-                            val newOlmInboundGroupSessionWrapper2 = OlmInboundGroupSessionWrapper2()
+                            val sessionKey = mxOlmInboundGroupSession2.mSession.sessionIdentifier()
+                            val newOlmInboundGroupSessionWrapper = OlmInboundGroupSessionWrapper(sessionKey, false)
                                     .apply {
                                         olmInboundGroupSession = mxOlmInboundGroupSession2.mSession
                                         roomId = mxOlmInboundGroupSession2.mRoomId
@@ -191,7 +192,7 @@ internal class RealmCryptoStoreMigration @Inject constructor(private val crossSi
                                         forwardingCurve25519KeyChain = mxOlmInboundGroupSession2.mForwardingCurve25519KeyChain
                                     }
 
-                            obj.setString("olmInboundGroupSessionData", serializeForRealm(newOlmInboundGroupSessionWrapper2))
+                            obj.setString("olmInboundGroupSessionData", serializeForRealm(newOlmInboundGroupSessionWrapper))
                         }
                     } catch (e: Exception) {
                         Timber.e(e, "Error")