diff --git a/Subsurface/Source/Map/Md5Hash.cs b/Subsurface/Source/Map/Md5Hash.cs
index 495a3f6a2..8f4e76fdf 100644
--- a/Subsurface/Source/Map/Md5Hash.cs
+++ b/Subsurface/Source/Map/Md5Hash.cs
@@ -94,9 +94,9 @@ namespace Barotrauma
             return sb.ToString();
         }
 
-        private string GetShortHash(string fullHash)
-        {
-            return fullHash;
+        public static string GetShortHash(string fullHash)
+        {            
+            return fullHash.Length < 7 ? fullHash : fullHash.Substring(0, 7);
         }
     }
 }
diff --git a/Subsurface/Source/Networking/FileTransfer/FileSender.cs b/Subsurface/Source/Networking/FileTransfer/FileSender.cs
index 0368f60f0..1d219ffad 100644
--- a/Subsurface/Source/Networking/FileTransfer/FileSender.cs
+++ b/Subsurface/Source/Networking/FileTransfer/FileSender.cs
@@ -271,7 +271,8 @@ namespace Barotrauma.Networking
             {
                 case (byte)FileTransferType.Submarine:
                     string fileName = inc.ReadString();
-                    var requestedSubmarine = Submarine.SavedSubmarines.Find(s => s.Name == fileName);
+                    string fileHash = inc.ReadString();
+                    var requestedSubmarine = Submarine.SavedSubmarines.Find(s => s.Name == fileName && s.MD5Hash.Hash == fileHash);
 
                     if (requestedSubmarine != null)
                     {
diff --git a/Subsurface/Source/Networking/GameClient.cs b/Subsurface/Source/Networking/GameClient.cs
index 631a26fec..bfeac6fb6 100644
--- a/Subsurface/Source/Networking/GameClient.cs
+++ b/Subsurface/Source/Networking/GameClient.cs
@@ -740,7 +740,7 @@ namespace Barotrauma.Networking
                 string subName = inc.ReadString();
                 string subHash = inc.ReadString();
 
-                var matchingSub = Submarine.SavedSubmarines.Find(s => s.Name == subName);
+                var matchingSub = Submarine.SavedSubmarines.Find(s => s.Name == subName && s.MD5Hash.Hash == subHash);
                 if (matchingSub != null)
                 {
                     submarines.Add(matchingSub);
@@ -987,13 +987,14 @@ namespace Barotrauma.Networking
             chatMsgQueue.Add(chatMessage);
         }
 
-        public void RequestFile(string file, FileTransferType fileType)
+        public void RequestFile(FileTransferType fileType, string file, string fileHash)
         {
             NetOutgoingMessage msg = client.CreateMessage();
             msg.Write((byte)ClientPacketHeader.FILE_REQUEST);
             msg.Write((byte)FileTransferMessageType.Initiate);
             msg.Write((byte)fileType);
             msg.Write(file);
+            msg.Write(fileHash);
             client.SendMessage(msg, NetDeliveryMethod.ReliableUnordered);
         }
 
@@ -1012,17 +1013,23 @@ namespace Barotrauma.Networking
             switch (transfer.FileType)
             {
                 case FileTransferType.Submarine:
-                    Submarine.SavedSubmarines.RemoveAll(s => s.Name + ".sub" == transfer.FileName);
+                    var newSub = new Submarine(transfer.FilePath);
+                    Submarine.SavedSubmarines.RemoveAll(s => s.Name == newSub.Name && s.MD5Hash.Hash == newSub.MD5Hash.Hash);
+                    Submarine.SavedSubmarines.Add(newSub);
+
                     for (int i = 0; i < 2; i++)
                     {
-                        var textBlock = ((i == 0) ?
-                            GameMain.NetLobbyScreen.ShuttleList.ListBox.children.Find(c => (c.UserData as Submarine).Name + ".sub" == transfer.FileName) :
-                            GameMain.NetLobbyScreen.SubList.children.Find(c => (c.UserData as Submarine).Name + ".sub" == transfer.FileName)) as GUITextBlock;
+                        List<GUIComponent> subListChildren = (i == 0) ? 
+                            GameMain.NetLobbyScreen.ShuttleList.ListBox.children : 
+                            GameMain.NetLobbyScreen.SubList.children;
+
+                        var textBlock = subListChildren.Find(c => 
+                            ((Submarine)c.UserData).Name == newSub.Name && 
+                            ((Submarine)c.UserData).MD5Hash.Hash == newSub.MD5Hash.Hash) as GUITextBlock;
 
                         if (textBlock == null) continue;
                         textBlock.TextColor = Color.White;
-                        var newSub = new Submarine(transfer.FilePath);
-                        Submarine.SavedSubmarines.Add(newSub);
+
                         textBlock.UserData = newSub;
                         textBlock.ToolTip = newSub.Description;
                     }
diff --git a/Subsurface/Source/Screens/NetLobbyScreen.cs b/Subsurface/Source/Screens/NetLobbyScreen.cs
index 0f27c933c..6160f4db9 100644
--- a/Subsurface/Source/Screens/NetLobbyScreen.cs
+++ b/Subsurface/Source/Screens/NetLobbyScreen.cs
@@ -716,7 +716,9 @@ namespace Barotrauma
             };
 
 
-            var matchingSub = Submarine.SavedSubmarines.Find(s => s.Name == sub.Name);
+            var matchingSub = Submarine.SavedSubmarines.Find(s => s.Name == sub.Name && s.MD5Hash.Hash == sub.MD5Hash.Hash);
+            if (matchingSub == null) matchingSub = Submarine.SavedSubmarines.Find(s => s.Name == sub.Name);
+
             if (matchingSub == null)
             {
                 subTextBlock.TextColor = Color.Gray;
@@ -1213,7 +1215,10 @@ namespace Barotrauma
                 return false;
             }
 
-            var matchingListSub = subList.children.Find(c => c.UserData != null && (c.UserData as Submarine).Name == subName) as GUITextBlock;
+            Submarine sub = Submarine.SavedSubmarines.Find(m => m.Name == subName && m.MD5Hash.Hash == md5Hash);
+            if (sub == null) sub = Submarine.SavedSubmarines.Find(m => m.Name == subName);
+
+            var matchingListSub = subList.children.Find(c => c.UserData == sub) as GUITextBlock;
             if (matchingListSub != null)
             {
                 subList.OnSelected -= VotableClicked;
@@ -1221,7 +1226,6 @@ namespace Barotrauma
                 subList.OnSelected += VotableClicked;
             }
 
-            Submarine sub = Submarine.SavedSubmarines.Find(m => m.Name == subName);
             if (sub == null || sub.MD5Hash.Hash != md5Hash)
             {
                 string errorMsg = "";
@@ -1237,9 +1241,9 @@ namespace Barotrauma
                 }
                 else
                 {
-                    errorMsg = "Your version of the submarine file \"" + sub.Name + "\" doesn't match the server's version! "
-                    + "Your MD5 hash: " + sub.MD5Hash.Hash + " \n"
-                    + "Server's MD5 hash: " + md5Hash + ". ";
+                    errorMsg = "Your version of the submarine file \"" + sub.Name + "\" doesn't match the server's version!\n"
+                    + "Your MD5 hash: " + sub.MD5Hash.ShortHash + "\n"
+                    + "Server's MD5 hash: " + Md5Hash.GetShortHash(md5Hash) + "\n";
                 }
 
                 errorMsg += "Do you want to download the file from the server host?";
@@ -1252,11 +1256,12 @@ namespace Barotrauma
 
                 var requestFileBox = new GUIMessageBox("Submarine not found!", errorMsg, new string[] { "Yes", "No" }, 400, 300);
                 requestFileBox.UserData = "request" + subName;
-                requestFileBox.Buttons[0].UserData = subName;
+                requestFileBox.Buttons[0].UserData = new string[] { subName, md5Hash };
                 requestFileBox.Buttons[0].OnClicked += requestFileBox.Close;
                 requestFileBox.Buttons[0].OnClicked += (GUIButton button, object userdata) =>
                     {
-                        GameMain.Client.RequestFile(userdata.ToString(), FileTransferType.Submarine);
+                        string[] fileInfo = (string[])userdata;
+                        GameMain.Client.RequestFile(FileTransferType.Submarine, fileInfo[0], fileInfo[1]);
                         return true;
                     };
                 requestFileBox.Buttons[1].OnClicked += requestFileBox.Close;