diff --git a/tests/monotouch-test/System.Net.Http/MessageHandlers.cs b/tests/monotouch-test/System.Net.Http/MessageHandlers.cs
index 527e8a737b8b..cf73cda63d5c 100644
--- a/tests/monotouch-test/System.Net.Http/MessageHandlers.cs
+++ b/tests/monotouch-test/System.Net.Http/MessageHandlers.cs
@@ -170,6 +170,11 @@ public void RejectSslCertificatesServicePointManager (Type handlerType)
 			TestRuntime.AssertSystemVersion (PlatformName.MacOSX, 10, 9, throwIfOtherPlatform: false);
 			TestRuntime.AssertSystemVersion (PlatformName.iOS, 7, 0, throwIfOtherPlatform: false);
 
+#if __MACOS__
+			if (handlerType == typeof (NSUrlSessionHandler) && TestRuntime.CheckSystemVersion (PlatformName.MacOSX, 10, 10, 0) && !TestRuntime.CheckSystemVersion (PlatformName.MacOSX, 10, 11, 0))
+				Assert.Ignore ("Fails on macOS 10.10: https://github.com/xamarin/maccore/issues/1645");
+#endif
+
 			bool validationCbWasExecuted = false;
 			bool customValidationCbWasExecuted = false;
 			bool invalidServicePointManagerCbWasExcuted = false;