diff --git a/src/FSharp.Control.TaskSeq/TaskSeqInternal.fs b/src/FSharp.Control.TaskSeq/TaskSeqInternal.fs
index ed92a9fe..8f5da6e8 100644
--- a/src/FSharp.Control.TaskSeq/TaskSeqInternal.fs
+++ b/src/FSharp.Control.TaskSeq/TaskSeqInternal.fs
@@ -978,13 +978,11 @@ module internal TaskSeqInternal =
                 go <- step
         }
 
-        interface IAsyncDisposable with
-            override _.DisposeAsync() =
+        interface IDisposable with
+            override _.Dispose() =
                 if not (isNull _rwLock) then
                     _rwLock.Dispose()
 
-                ValueTask.CompletedTask
-
     let except itemsToExclude (source: TaskSeq<_>) =
         checkNonNull (nameof source) source
         checkNonNull (nameof itemsToExclude) itemsToExclude