diff --git a/Source/Examples/OpenGL/1.1/DisplayLists.cs b/Source/Examples/OpenGL/1.1/DisplayLists.cs
index 4a255eef..7a9c718a 100644
--- a/Source/Examples/OpenGL/1.1/DisplayLists.cs
+++ b/Source/Examples/OpenGL/1.1/DisplayLists.cs
@@ -107,7 +107,7 @@ namespace Examples.Tutorial
 
         #region OnUnload
 
-        public override void OnUnload(EventArgs e)
+        protected override void OnUnload(EventArgs e)
         {
             GL.DeleteLists(lists[0], num_lists);
         }
diff --git a/Source/Examples/OpenGL/1.1/Textures.cs b/Source/Examples/OpenGL/1.1/Textures.cs
index 38d7f8be..a60f0bd9 100644
--- a/Source/Examples/OpenGL/1.1/Textures.cs
+++ b/Source/Examples/OpenGL/1.1/Textures.cs
@@ -62,7 +62,7 @@ namespace Examples.Tutorial
 
         #region OnUnload
 
-        public override void OnUnload(EventArgs e)
+        protected override void OnUnload(EventArgs e)
         {
             GL.DeleteTextures(1, ref texture);
         }
diff --git a/Source/Examples/OpenGL/EXT/FramebufferObject.cs b/Source/Examples/OpenGL/EXT/FramebufferObject.cs
index 37073f6d..4df4d61a 100644
--- a/Source/Examples/OpenGL/EXT/FramebufferObject.cs
+++ b/Source/Examples/OpenGL/EXT/FramebufferObject.cs
@@ -201,7 +201,7 @@ namespace Examples.Tutorial
             GL.BindTexture(TextureTarget.Texture2D, 0); // bind default texture
         }
 
-        public override void OnUnload(EventArgs e)
+        protected override void OnUnload(EventArgs e)
         {
             // Clean up what we allocated before exiting
             if (ColorTexture != 0)
diff --git a/Source/Examples/OpenGL/EXT/GeometryShader.cs b/Source/Examples/OpenGL/EXT/GeometryShader.cs
index ee4b9708..113af374 100644
--- a/Source/Examples/OpenGL/EXT/GeometryShader.cs
+++ b/Source/Examples/OpenGL/EXT/GeometryShader.cs
@@ -188,7 +188,7 @@ namespace Examples.Tutorial
             }
         }
 
-        public override void OnUnload(EventArgs e)
+        protected override void OnUnload(EventArgs e)
         {
             if (shaderProgram != 0)
                 GL.DeleteProgram(shaderProgram);
diff --git a/Source/Examples/OpenGL/EXT/GeometryShaderAdvanced.cs b/Source/Examples/OpenGL/EXT/GeometryShaderAdvanced.cs
index 1a092577..0f462824 100644
--- a/Source/Examples/OpenGL/EXT/GeometryShaderAdvanced.cs
+++ b/Source/Examples/OpenGL/EXT/GeometryShaderAdvanced.cs
@@ -869,7 +869,7 @@ namespace Examples.Tutorial
 
         }
 
-        public override void OnUnload(EventArgs e)
+        protected override void OnUnload(EventArgs e)
         {
             if (shaderProgramBox != 0)
                 GL.DeleteProgram(shaderProgramBox);
diff --git a/Source/Examples/OpenGL/GLSL/JuliaSetFractal.cs b/Source/Examples/OpenGL/GLSL/JuliaSetFractal.cs
index 9df76d6a..9b1d6d5f 100644
--- a/Source/Examples/OpenGL/GLSL/JuliaSetFractal.cs
+++ b/Source/Examples/OpenGL/GLSL/JuliaSetFractal.cs
@@ -194,7 +194,7 @@ namespace Examples.Tutorial
 
         #region OnUnload
 
-        public override void OnUnload(EventArgs e)
+        protected override void OnUnload(EventArgs e)
         {
             if (TextureObject != 0)
                 GL.DeleteTextures(1, ref TextureObject);
diff --git a/Source/Examples/OpenGL/GLSL/SimpleGLSL.cs b/Source/Examples/OpenGL/GLSL/SimpleGLSL.cs
index 02e9dbbd..596630e5 100644
--- a/Source/Examples/OpenGL/GLSL/SimpleGLSL.cs
+++ b/Source/Examples/OpenGL/GLSL/SimpleGLSL.cs
@@ -170,7 +170,7 @@ namespace Examples.Tutorial
 
         #region OnUnload
 
-        public override void OnUnload(EventArgs e)
+        protected override void OnUnload(EventArgs e)
         {
             if (shader_program != 0)
                 GL.DeleteProgram(shader_program);