diff --git a/src/Avalonia.Controls/Templates/ITemplate`1.cs b/src/Avalonia.Controls/Templates/ITemplate`1.cs
index a241a9a6e8..a450e14b83 100644
--- a/src/Avalonia.Controls/Templates/ITemplate`1.cs
+++ b/src/Avalonia.Controls/Templates/ITemplate`1.cs
@@ -6,7 +6,7 @@ namespace Avalonia.Controls
     /// Creates a control.
     /// </summary>
     /// <typeparam name="TControl">The type of control.</typeparam>
-    public interface ITemplate<TControl> : ITemplate where TControl : IControl
+    public interface ITemplate<TControl> : ITemplate where TControl : IControl?
     {
         /// <summary>
         /// Creates the control.
@@ -16,4 +16,4 @@ namespace Avalonia.Controls
         /// </returns>
         new TControl Build();
     }
-}
\ No newline at end of file
+}