diff --git a/src/Avalonia.Controls/Platform/ManagedDispatcherImpl.cs b/src/Avalonia.Controls/Platform/ManagedDispatcherImpl.cs
index fdc098777a..c8225f775b 100644
--- a/src/Avalonia.Controls/Platform/ManagedDispatcherImpl.cs
+++ b/src/Avalonia.Controls/Platform/ManagedDispatcherImpl.cs
@@ -99,9 +99,15 @@ public class ManagedDispatcherImpl : IControlledDispatcherImpl
                 continue;
             }
 
-            if (_nextTimer != null)
+            TimeSpan? nextTimer;
+            lock (_lock)
+            {
+                nextTimer = _nextTimer;
+            }
+
+            if (nextTimer != null)
             {
-                var waitFor = _clock.Elapsed - _nextTimer.Value;
+                var waitFor = nextTimer.Value - _clock.Elapsed;
                 if (waitFor.TotalMilliseconds < 1)
                     continue;
                 _wakeup.WaitOne(waitFor);
@@ -112,4 +118,4 @@ public class ManagedDispatcherImpl : IControlledDispatcherImpl
 
         registration.Dispose();
     }
-}
\ No newline at end of file
+}