diff --git a/app/src/main/java/org/thoughtcrime/securesms/database/Storage.kt b/app/src/main/java/org/thoughtcrime/securesms/database/Storage.kt
index d81796d85c..430d9cd63b 100644
--- a/app/src/main/java/org/thoughtcrime/securesms/database/Storage.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/database/Storage.kt
@@ -564,7 +564,7 @@ open class Storage(context: Context, helper: SQLCipherOpenHelper, private val co
                 val admins = group.members.filter { it.value /*admin = true*/ }.keys.map { Address.fromSerialized(it) }
                 val groupId = GroupUtil.doubleEncodeGroupID(group.sessionId)
                 val title = group.name
-                val formationTimestamp = SnodeAPI.nowWithOffset // TODO: formation timestamp for legacy ? current time?
+                val formationTimestamp = group.joinedAt
                 createGroup(groupId, title, members, null, null, admins, formationTimestamp)
                 setProfileSharing(Address.fromSerialized(groupId), true)
                 // Add the group to the user's set of public keys to poll for
@@ -835,7 +835,8 @@ open class Storage(context: Context, helper: SQLCipherOpenHelper, private val co
             priority = ConfigBase.PRIORITY_VISIBLE,
             encPubKey = encryptionKeyPair.publicKey.serialize(),
             encSecKey = encryptionKeyPair.privateKey.serialize(),
-            disappearingTimer = 0L
+            disappearingTimer = 0L,
+            joinedAt = formationTimestamp
         )
         // shouldn't exist, don't use getOrConstruct + copy
         userGroups.set(groupInfo)
diff --git a/app/src/main/java/org/thoughtcrime/securesms/util/ConfigurationMessageUtilities.kt b/app/src/main/java/org/thoughtcrime/securesms/util/ConfigurationMessageUtilities.kt
index 3644cdc127..1e5e9b475c 100644
--- a/app/src/main/java/org/thoughtcrime/securesms/util/ConfigurationMessageUtilities.kt
+++ b/app/src/main/java/org/thoughtcrime/securesms/util/ConfigurationMessageUtilities.kt
@@ -256,7 +256,8 @@ object ConfigurationMessageUtilities {
                 priority = if (isPinned) ConfigBase.PRIORITY_PINNED else ConfigBase.PRIORITY_VISIBLE,
                 encPubKey = encryptionKeyPair.publicKey.serialize(),
                 encSecKey = encryptionKeyPair.privateKey.serialize(),
-                disappearingTimer = recipient.expireMessages.toLong()
+                disappearingTimer = recipient.expireMessages.toLong(),
+                joinedAt = group.formationTimestamp
             )
         }
         (allOpenGroups + allLgc).forEach { groupInfo ->
diff --git a/libsession-util/src/main/cpp/user_groups.h b/libsession-util/src/main/cpp/user_groups.h
index a79d01a0a7..1ec852340b 100644
--- a/libsession-util/src/main/cpp/user_groups.h
+++ b/libsession-util/src/main/cpp/user_groups.h
@@ -51,12 +51,14 @@ inline session::config::legacy_group_info deserialize_legacy_group_info(JNIEnv *
     auto enc_sec_key_field = env->GetFieldID(clazz, "encSecKey", "[B");
     auto priority_field = env->GetFieldID(clazz, "priority", "I");
     auto disappearing_timer_field = env->GetFieldID(clazz, "disappearingTimer", "J");
+    auto joined_at_field = env->GetFieldID(clazz, "joinedAt", "L");
     jstring id = static_cast<jstring>(env->GetObjectField(info, id_field));
     jstring name = static_cast<jstring>(env->GetObjectField(info, name_field));
     jobject members_map = env->GetObjectField(info, members_field);
     jbyteArray enc_pub_key = static_cast<jbyteArray>(env->GetObjectField(info, enc_pub_key_field));
     jbyteArray enc_sec_key = static_cast<jbyteArray>(env->GetObjectField(info, enc_sec_key_field));
     int priority = env->GetIntField(info, priority_field);
+    long joined_at = env->GetLongField(info, joined_at_field);
 
     auto id_bytes = env->GetStringUTFChars(id, nullptr);
     auto name_bytes = env->GetStringUTFChars(name, nullptr);
@@ -75,6 +77,7 @@ inline session::config::legacy_group_info deserialize_legacy_group_info(JNIEnv *
     info_deserialized.enc_seckey = enc_sec_key_bytes;
     info_deserialized.priority = priority;
     info_deserialized.disappearing_timer = std::chrono::seconds(env->GetLongField(info, disappearing_timer_field));
+    info_deserialized.joined_at = joined_at;
     env->ReleaseStringUTFChars(id, id_bytes);
     env->ReleaseStringUTFChars(name, name_bytes);
     return info_deserialized;
@@ -116,10 +119,11 @@ inline jobject serialize_legacy_group_info(JNIEnv *env, session::config::legacy_
     jbyteArray enc_pubkey = util::bytes_from_ustring(env, info.enc_pubkey);
     jbyteArray enc_seckey = util::bytes_from_ustring(env, info.enc_seckey);
     int priority = info.priority;
+    long joined_at = info.joined_at;
 
     jclass legacy_group_class = env->FindClass("network/loki/messenger/libsession_util/util/GroupInfo$LegacyGroupInfo");
-    jmethodID constructor = env->GetMethodID(legacy_group_class, "<init>", "(Ljava/lang/String;Ljava/lang/String;Ljava/util/Map;[B[BIJ)V");
-    jobject serialized = env->NewObject(legacy_group_class, constructor, session_id, name, members, enc_pubkey, enc_seckey, priority, (jlong) info.disappearing_timer.count());
+    jmethodID constructor = env->GetMethodID(legacy_group_class, "<init>", "(Ljava/lang/String;Ljava/lang/String;Ljava/util/Map;[B[BIJL)V");
+    jobject serialized = env->NewObject(legacy_group_class, constructor, session_id, name, members, enc_pubkey, enc_seckey, priority, joined_at, (jlong) info.disappearing_timer.count());
     return serialized;
 }
 
diff --git a/libsession-util/src/main/java/network/loki/messenger/libsession_util/util/GroupInfo.kt b/libsession-util/src/main/java/network/loki/messenger/libsession_util/util/GroupInfo.kt
index 8201baf940..c8ace0a9a7 100644
--- a/libsession-util/src/main/java/network/loki/messenger/libsession_util/util/GroupInfo.kt
+++ b/libsession-util/src/main/java/network/loki/messenger/libsession_util/util/GroupInfo.kt
@@ -11,7 +11,8 @@ sealed class GroupInfo {
         val encPubKey: ByteArray,
         val encSecKey: ByteArray,
         val priority: Int,
-        val disappearingTimer: Long
+        val disappearingTimer: Long,
+        val joinedAt: Long
     ): GroupInfo() {
         companion object {
             @Suppress("FunctionName")
@@ -30,6 +31,8 @@ sealed class GroupInfo {
             if (!encPubKey.contentEquals(other.encPubKey)) return false
             if (!encSecKey.contentEquals(other.encSecKey)) return false
             if (priority != other.priority) return false
+            if (disappearingTimer != other.disappearingTimer) return false
+            if (joinedAt != other.joinedAt) return false
 
             return true
         }
@@ -41,6 +44,8 @@ sealed class GroupInfo {
             result = 31 * result + encPubKey.contentHashCode()
             result = 31 * result + encSecKey.contentHashCode()
             result = 31 * result + priority
+            result = 31 * result + disappearingTimer.hashCode()
+            result = 31 * result + joinedAt.hashCode()
             return result
         }
     }