diff --git a/ErsatzTV.Application/Playouts/Commands/BuildPlayoutHandler.cs b/ErsatzTV.Application/Playouts/Commands/BuildPlayoutHandler.cs
index 4d84d43a..94c326fe 100644
--- a/ErsatzTV.Application/Playouts/Commands/BuildPlayoutHandler.cs
+++ b/ErsatzTV.Application/Playouts/Commands/BuildPlayoutHandler.cs
@@ -57,6 +57,8 @@ public class BuildPlayoutHandler : IRequestHandler<BuildPlayout, Either<BaseErro
     {
         try
         {
+            _entityLocker.LockPlayout(playout.Id);
+
             await _playoutBuilder.Build(playout, request.Mode, cancellationToken);
 
             // let any active segmenter processes know that the playout has been modified