diff --git a/.appveyor.yml b/.appveyor.yml
index 77e49e54..db6a501f 100644
--- a/.appveyor.yml
+++ b/.appveyor.yml
@@ -52,7 +52,7 @@ for:
     only:
     - image: Ubuntu
   build_script:
-  - msbuild Halcyon.sln
+  - msbuild /p:DefineConstants="_MONO_CLI_FLAG_" Halcyon.sln
 
 after_build:
 - ps: |
diff --git a/OpenSim/Framework/Util.cs b/OpenSim/Framework/Util.cs
index 7588bb20..3c2848ca 100644
--- a/OpenSim/Framework/Util.cs
+++ b/OpenSim/Framework/Util.cs
@@ -53,7 +53,7 @@
 using System.Drawing;
 using System.Runtime.InteropServices;
 
-#if !__MonoCS__
+#if !_MONO_CLI_FLAG_
 using System.DirectoryServices.AccountManagement;
 #endif
 
@@ -186,7 +186,7 @@ public static UInt64 GetLongTickCount()
         /// <param name='password'>string</param>
         public static bool AuthenticateAsSystemUser(string username, string password)
         {
-            #if __MonoCS__
+            #if _MONO_CLI_FLAG_
                 // TODO: find a way to check the user info cross platform.  In the mean time better security by NOT allowing remote admin.
                 return false;
             #else