diff --git a/app/src/main/kotlin/com/simplemobiletools/smsmessenger/extensions/Context.kt b/app/src/main/kotlin/com/simplemobiletools/smsmessenger/extensions/Context.kt
index 142cd360..48f31694 100644
--- a/app/src/main/kotlin/com/simplemobiletools/smsmessenger/extensions/Context.kt
+++ b/app/src/main/kotlin/com/simplemobiletools/smsmessenger/extensions/Context.kt
@@ -105,6 +105,13 @@ fun Context.getMessages(threadId: Int): ArrayList<Message> {
     messages = messages.filter { it.participants.isNotEmpty() }
         .sortedWith(compareBy<Message> { it.date }.thenBy { it.id }).toMutableList() as ArrayList<Message>
 
+    // use a separate thread for saving messages in a db
+    Thread {
+        messages.chunked(30).forEach { currentMessages ->
+            messagesDB.insertMessages(*currentMessages.toTypedArray())
+        }
+    }.start()
+
     return messages
 }
 
diff --git a/app/src/main/kotlin/com/simplemobiletools/smsmessenger/helpers/Converters.kt b/app/src/main/kotlin/com/simplemobiletools/smsmessenger/helpers/Converters.kt
index 27c94855..b11cbeb3 100644
--- a/app/src/main/kotlin/com/simplemobiletools/smsmessenger/helpers/Converters.kt
+++ b/app/src/main/kotlin/com/simplemobiletools/smsmessenger/helpers/Converters.kt
@@ -11,7 +11,7 @@ class Converters {
     private val gson = Gson()
     private val attachmentType = object : TypeToken<List<Attachment>>() {}.type
     private val simpleContactType = object : TypeToken<List<SimpleContact>>() {}.type
-    private val messageAttachmentType = object : TypeToken<MessageAttachment>() {}.type
+    private val messageAttachmentType = object : TypeToken<MessageAttachment?>() {}.type
 
     @TypeConverter
     fun jsonToAttachmentList(value: String) = gson.fromJson<ArrayList<Attachment>>(value, attachmentType)
@@ -29,5 +29,5 @@ class Converters {
     fun jsonToMessageAttachment(value: String) = gson.fromJson<MessageAttachment>(value, messageAttachmentType)
 
     @TypeConverter
-    fun messageAttachmentToJson(messageAttachment: MessageAttachment) = gson.toJson(messageAttachment)
+    fun messageAttachmentToJson(messageAttachment: MessageAttachment?) = gson.toJson(messageAttachment)
 }
diff --git a/app/src/main/kotlin/com/simplemobiletools/smsmessenger/interfaces/MessagesDao.kt b/app/src/main/kotlin/com/simplemobiletools/smsmessenger/interfaces/MessagesDao.kt
index cd8398ef..bb508011 100644
--- a/app/src/main/kotlin/com/simplemobiletools/smsmessenger/interfaces/MessagesDao.kt
+++ b/app/src/main/kotlin/com/simplemobiletools/smsmessenger/interfaces/MessagesDao.kt
@@ -1,11 +1,22 @@
 package com.simplemobiletools.smsmessenger.interfaces
 
 import androidx.room.Dao
+import androidx.room.Insert
+import androidx.room.OnConflictStrategy
 import androidx.room.Query
 import com.simplemobiletools.smsmessenger.models.Message
 
 @Dao
 interface MessagesDao {
+    @Insert(onConflict = OnConflictStrategy.REPLACE)
+    fun insertOrUpdate(message: Message)
+
+    @Insert(onConflict = OnConflictStrategy.REPLACE)
+    fun insertMessages(vararg message: Message)
+
     @Query("SELECT * FROM messages")
     fun getAll(): List<Message>
+
+    @Query("SELECT * FROM messages WHERE thread = :threadId")
+    fun getThreadMessages(threadId: Long): List<Message>
 }