diff --git a/src/Avalonia.Build.Tasks/CompileAvaloniaXamlTask.cs b/src/Avalonia.Build.Tasks/CompileAvaloniaXamlTask.cs
index 54db830f2f..4dedb218a1 100644
--- a/src/Avalonia.Build.Tasks/CompileAvaloniaXamlTask.cs
+++ b/src/Avalonia.Build.Tasks/CompileAvaloniaXamlTask.cs
@@ -2,6 +2,7 @@ using System;
 using System.Diagnostics;
 using System.IO;
 using System.Linq;
+using System.Reflection;
 using System.Threading;
 using Microsoft.Build.Framework;
 
@@ -12,13 +13,23 @@ namespace Avalonia.Build.Tasks
         public bool Execute()
         {
             OutputPath = OutputPath ?? AssemblyFile;
+            var outputPdb = GetPdbPath(OutputPath);
             var input = AssemblyFile;
+            var inputPdb = GetPdbPath(input);
             // Make a copy and delete the original file to prevent MSBuild from thinking that everything is OK 
             if (OriginalCopyPath != null)
             {
                 File.Copy(AssemblyFile, OriginalCopyPath, true);
                 input = OriginalCopyPath;
                 File.Delete(AssemblyFile);
+
+                if (File.Exists(inputPdb))
+                {
+                    var copyPdb = GetPdbPath(OriginalCopyPath);
+                    File.Copy(inputPdb, copyPdb, true);
+                    File.Delete(inputPdb);
+                    inputPdb = copyPdb;
+                }
             }
 
             var res = XamlCompilerTaskExecutor.Compile(BuildEngine, input,
@@ -27,14 +38,30 @@ namespace Avalonia.Build.Tasks
             if (!res.Success)
                 return false;
             if (res.Data == null)
-                File.Copy(input, OutputPath);
+            {
+                File.Copy(input, OutputPath, true);
+                if(File.Exists(inputPdb))
+                    File.Copy(inputPdb, OutputPath, true);
+            }
             else
+            {
                 File.WriteAllBytes(OutputPath, res.Data);
+                if (res.Symbols != null)
+                    File.WriteAllBytes(outputPdb, res.Symbols);
+            }
 
             return true;
         }
-        
-        
+
+        string GetPdbPath(string p)
+        {
+            var d = Path.GetDirectoryName(p);
+            var f = Path.GetFileNameWithoutExtension(p);
+            var rv = f + ".pdb";
+            if (d != null)
+                rv = Path.Combine(d, rv);
+            return rv;
+        }
         
         [Required]
         public string AssemblyFile { get; set; }
diff --git a/src/Avalonia.Build.Tasks/XamlCompilerTaskExecutor.cs b/src/Avalonia.Build.Tasks/XamlCompilerTaskExecutor.cs
index 63672ee98b..f3967e9bb3 100644
--- a/src/Avalonia.Build.Tasks/XamlCompilerTaskExecutor.cs
+++ b/src/Avalonia.Build.Tasks/XamlCompilerTaskExecutor.cs
@@ -30,11 +30,13 @@ namespace Avalonia.Build.Tasks
         {
             public bool Success { get; set; }
             public byte[] Data { get; set; }
+            public byte[] Symbols { get; }
 
-            public CompileResult(bool success, byte[] data = null)
+            public CompileResult(bool success, byte[] data = null, byte[] symbols = null)
             {
                 Success = success;
                 Data = data;
+                Symbols = symbols;
             }
         }
         
@@ -283,8 +285,15 @@ namespace Avalonia.Build.Tasks
             loaderDispatcherMethod.Body.Instructions.Add(Instruction.Create(OpCodes.Ret));
             
             var ms = new MemoryStream();
-            asm.Write(ms);
-            return new CompileResult(true, ms.ToArray());
+            var symbolStream = new MemoryStream();
+            asm.Write(ms, new WriterParameters
+            {
+                SymbolStream = symbolStream,
+                WriteSymbols = true,
+                SymbolWriterProvider = new PortablePdbWriterProvider()
+            });
+
+            return new CompileResult(true, ms.ToArray(), symbolStream.Length == 0 ? null : symbolStream.ToArray());
         }
         
     }
diff --git a/src/Markup/Avalonia.Markup.Xaml/XamlIl/xamlil.github b/src/Markup/Avalonia.Markup.Xaml/XamlIl/xamlil.github
index c28bd89bf4..22a7267a22 160000
--- a/src/Markup/Avalonia.Markup.Xaml/XamlIl/xamlil.github
+++ b/src/Markup/Avalonia.Markup.Xaml/XamlIl/xamlil.github
@@ -1 +1 @@
-Subproject commit c28bd89bf4c315c188394139f500f7f4efed4b94
+Subproject commit 22a7267a22124cd2413f83082298b5c0e10a8c02