diff --git a/src/ReactiveUI.Wpf/Registrations.cs b/src/ReactiveUI.Wpf/Registrations.cs
index 2867b3522a..5634de399e 100644
--- a/src/ReactiveUI.Wpf/Registrations.cs
+++ b/src/ReactiveUI.Wpf/Registrations.cs
@@ -20,7 +20,9 @@ public void Register(Action<Func<object>, Type> registerFunction)
 
             RxApp.TaskpoolScheduler = TaskPoolScheduler.Default;
 
-            RxApp.MainThreadScheduler = new WaitForDispatcherScheduler(() => DispatcherScheduler.Current);
+            if (!Splat.ModeDetector.InUnitTestRunner()) {
+                RxApp.MainThreadScheduler = new WaitForDispatcherScheduler(() => DispatcherScheduler.Current);
+            }
         }
     }
 }
diff --git a/src/ReactiveUI/Platforms/net461/PlatformRegistrations.cs b/src/ReactiveUI/Platforms/net461/PlatformRegistrations.cs
index 7e840ea570..675e4c0e84 100644
--- a/src/ReactiveUI/Platforms/net461/PlatformRegistrations.cs
+++ b/src/ReactiveUI/Platforms/net461/PlatformRegistrations.cs
@@ -13,7 +13,10 @@ public void Register(Action<Func<object>, Type> registerFunction)
         {
             registerFunction(() => new ComponentModelTypeConverter(), typeof(IBindingTypeConverter));
             RxApp.TaskpoolScheduler = TaskPoolScheduler.Default;
-            RxApp.MainThreadScheduler = DefaultScheduler.Instance;
+
+            if (!Splat.ModeDetector.InUnitTestRunner()) {
+                RxApp.MainThreadScheduler = DefaultScheduler.Instance;
+            }
         }
     }
 }