diff --git a/Source/OpenTK/GameWindow.cs b/Source/OpenTK/GameWindow.cs
index ad3f77a2..b8feeb96 100644
--- a/Source/OpenTK/GameWindow.cs
+++ b/Source/OpenTK/GameWindow.cs
@@ -61,7 +61,7 @@ namespace OpenTK
 
         ResizeEventArgs resizeEventArgs = new ResizeEventArgs();
 
-        bool isExiting;
+        bool isExiting = false;
         bool hasMainLoop;
         bool disposed;