diff --git a/Source/GLControl/GLControl.cs b/Source/GLControl/GLControl.cs
index 340b82f9..e69225cc 100644
--- a/Source/GLControl/GLControl.cs
+++ b/Source/GLControl/GLControl.cs
@@ -78,17 +78,20 @@ namespace OpenTK
         /// <param name="flags">The GraphicsContextFlags for the OpenGL GraphicsContext.</param>
         public GLControl(GraphicsMode mode, int major, int minor, GraphicsContextFlags flags)
         {
+            if (mode == null)
+                throw new ArgumentNullException("mode");
+            
             SetStyle(ControlStyles.Opaque, true);
             SetStyle(ControlStyles.UserPaint, true);
             SetStyle(ControlStyles.AllPaintingInWmPaint, true);
             DoubleBuffered = false;
 
-            InitializeComponent();
-
             this.format = mode;
             this.major = major;
             this.minor = minor;
             this.flags = flags;
+
+            InitializeComponent();
         }
 
         #endregion
diff --git a/Source/GLControl/GLControlFactory.cs b/Source/GLControl/GLControlFactory.cs
index d854d7ae..4040fe99 100644
--- a/Source/GLControl/GLControlFactory.cs
+++ b/Source/GLControl/GLControlFactory.cs
@@ -38,6 +38,11 @@ namespace OpenTK
     {
         public IGLControl CreateGLControl(GraphicsMode mode, Control control)
         {
+            if (mode == null)
+                throw new ArgumentNullException("mode");
+            if (control == null)
+                throw new ArgumentNullException("control");
+            
             if (Configuration.RunningOnWindows) return new WinGLControl(mode, control);
             else if (Configuration.RunningOnX11) return new X11GLControl(mode, control);
             else if (Configuration.RunningOnMacOS) return new CarbonGLControl(mode, control);