diff --git a/simplex-chat.cabal b/simplex-chat.cabal
index 7de66a5bd..2798a29f7 100644
--- a/simplex-chat.cabal
+++ b/simplex-chat.cabal
@@ -88,6 +88,7 @@ library
       Simplex.Chat.Migrations.M20230317_hidden_profiles
       Simplex.Chat.Migrations.M20230318_file_description
       Simplex.Chat.Migrations.M20230321_agent_file_deleted
+      Simplex.Chat.Migrations.M20230328_files_protocol
       Simplex.Chat.Mobile
       Simplex.Chat.Mobile.WebRTC
       Simplex.Chat.Options
diff --git a/src/Simplex/Chat/Migrations/M20230328_files_protocol.hs b/src/Simplex/Chat/Migrations/M20230328_files_protocol.hs
new file mode 100644
index 000000000..569037830
--- /dev/null
+++ b/src/Simplex/Chat/Migrations/M20230328_files_protocol.hs
@@ -0,0 +1,18 @@
+{-# LANGUAGE QuasiQuotes #-}
+
+module Simplex.Chat.Migrations.M20230328_files_protocol where
+
+import Database.SQLite.Simple (Query)
+import Database.SQLite.Simple.QQ (sql)
+
+m20230328_files_protocol :: Query
+m20230328_files_protocol =
+  [sql|
+ALTER TABLE files ADD COLUMN protocol TEXT NOT NULL DEFAULT 'smp';
+|]
+
+down_m20230328_files_protocol :: Query
+down_m20230328_files_protocol =
+  [sql|
+ALTER TABLE files DROP COLUMN protocol;
+|]
diff --git a/src/Simplex/Chat/Migrations/chat_schema.sql b/src/Simplex/Chat/Migrations/chat_schema.sql
index ed1b30354..4fc96eb5d 100644
--- a/src/Simplex/Chat/Migrations/chat_schema.sql
+++ b/src/Simplex/Chat/Migrations/chat_schema.sql
@@ -200,7 +200,8 @@ CREATE TABLE files(
   file_inline TEXT,
   agent_snd_file_id BLOB NULL,
   private_snd_file_descr TEXT NULL,
-  agent_snd_file_deleted INTEGER DEFAULT 0 CHECK(agent_snd_file_deleted NOT NULL)
+  agent_snd_file_deleted INTEGER DEFAULT 0 CHECK(agent_snd_file_deleted NOT NULL),
+  protocol TEXT NOT NULL DEFAULT 'smp'
 );
 CREATE TABLE snd_files(
   file_id INTEGER NOT NULL REFERENCES files ON DELETE CASCADE,
diff --git a/src/Simplex/Chat/Store.hs b/src/Simplex/Chat/Store.hs
index 1d45e2fe9..becdcbb45 100644
--- a/src/Simplex/Chat/Store.hs
+++ b/src/Simplex/Chat/Store.hs
@@ -363,6 +363,7 @@ import Simplex.Chat.Migrations.M20230303_group_link_role
 import Simplex.Chat.Migrations.M20230317_hidden_profiles
 import Simplex.Chat.Migrations.M20230318_file_description
 import Simplex.Chat.Migrations.M20230321_agent_file_deleted
+import Simplex.Chat.Migrations.M20230328_files_protocol
 import Simplex.Chat.Protocol
 import Simplex.Chat.Types
 import Simplex.Chat.Util (week)
@@ -432,7 +433,8 @@ schemaMigrations =
     ("20230303_group_link_role", m20230303_group_link_role, Nothing),
     ("20230317_hidden_profiles", m20230317_hidden_profiles, Just down_m20230317_hidden_profiles),
     ("20230318_file_description", m20230318_file_description, Just down_m20230318_file_description),
-    ("20230321_agent_file_deleted", m20230321_agent_file_deleted, Just down_m20230321_agent_file_deleted)
+    ("20230321_agent_file_deleted", m20230321_agent_file_deleted, Just down_m20230321_agent_file_deleted),
+    ("20230328_files_protocol", m20230328_files_protocol, Just down_m20230328_files_protocol)
   ]
 
 -- | The list of migrations in ascending order by date