diff --git a/src/OpenGL/CGLContext.cs b/src/OpenGL/CGLContext.cs
index 0a0c229da499..828188082c4b 100644
--- a/src/OpenGL/CGLContext.cs
+++ b/src/OpenGL/CGLContext.cs
@@ -30,9 +30,17 @@
 
 using ObjCRuntime;
 using Foundation;
+using System.Runtime.Versioning;
 
 namespace OpenGL {
-	[Deprecated (PlatformName.MacOSX, 10, 14, message : "Use 'Metal' Framework instead.")]
+#if !NET
+	[Deprecated (PlatformName.MacOSX, 10, 14, message: "Use 'Metal' Framework instead.")]
+#else
+	[UnsupportedOSPlatform ("macos10.14")]
+#if MONOMAC
+	[Obsolete ("Starting with macos10.14 Use 'Metal' Framework instead.", DiagnosticId = "BI1234", UrlFormat = "https://github.com/xamarin/xamarin-macios/wiki/Obsolete")]
+#endif
+#endif
 	public class CGLContext : INativeObject, IDisposable {
 		IntPtr handle;
 
diff --git a/src/OpenGL/CGLEnums.cs b/src/OpenGL/CGLEnums.cs
index 21fca472e521..b240ad8a2237 100644
--- a/src/OpenGL/CGLEnums.cs
+++ b/src/OpenGL/CGLEnums.cs
@@ -22,10 +22,18 @@
 //
 using System;
 using ObjCRuntime;
+using System.Runtime.Versioning;
 
 namespace OpenGL {
 
-	[Deprecated (PlatformName.MacOSX, 10, 14, message : "Use 'Metal' Framework instead.")]
+#if !NET
+	[Deprecated (PlatformName.MacOSX, 10, 14, message: "Use 'Metal' Framework instead.")]
+#else
+	[UnsupportedOSPlatform ("macos10.14")]
+#if MONOMAC
+	[Obsolete ("Starting with macos10.14 Use 'Metal' Framework instead.", DiagnosticId = "BI1234", UrlFormat = "https://github.com/xamarin/xamarin-macios/wiki/Obsolete")]
+#endif
+#endif
 	public enum CGLErrorCode : uint
 	{
 		NoError            = 0,		/* no error */
@@ -50,7 +58,14 @@ public enum CGLErrorCode : uint
 
 	}
 
-	[Deprecated (PlatformName.MacOSX, 10, 14, message : "Use 'Metal' Framework instead.")]
+#if !NET
+	[Deprecated (PlatformName.MacOSX, 10, 14, message: "Use 'Metal' Framework instead.")]
+#else
+	[UnsupportedOSPlatform ("macos10.14")]
+#if MONOMAC
+	[Obsolete ("Starting with macos10.14 Use 'Metal' Framework instead.", DiagnosticId = "BI1234", UrlFormat = "https://github.com/xamarin/xamarin-macios/wiki/Obsolete")]
+#endif
+#endif
 	public enum CGLPixelFormatAttribute : uint
 	{
 		AllRenderers = 1,
diff --git a/src/OpenGL/CGLPixelFormat.cs b/src/OpenGL/CGLPixelFormat.cs
index 8c6ecca7f7fb..1263c7cdc287 100644
--- a/src/OpenGL/CGLPixelFormat.cs
+++ b/src/OpenGL/CGLPixelFormat.cs
@@ -30,9 +30,17 @@
 using System.Collections.Generic;
 using ObjCRuntime;
 using Foundation;
+using System.Runtime.Versioning;
 
 namespace OpenGL {
-	[Deprecated (PlatformName.MacOSX, 10, 14, message : "Use 'Metal' Framework instead.")]
+#if !NET
+	[Deprecated (PlatformName.MacOSX, 10, 14, message: "Use 'Metal' Framework instead.")]
+#else
+	[UnsupportedOSPlatform ("macos10.14")]
+#if MONOMAC
+	[Obsolete ("Starting with macos10.14 Use 'Metal' Framework instead.", DiagnosticId = "BI1234", UrlFormat = "https://github.com/xamarin/xamarin-macios/wiki/Obsolete")]
+#endif
+#endif
 	public class CGLPixelFormat : INativeObject, IDisposable {
 		internal IntPtr handle;