diff --git a/msbuild/Xamarin.MacDev.Tasks.Core/Xamarin.MacDev.Tasks.Core.csproj b/msbuild/Xamarin.MacDev.Tasks.Core/Xamarin.MacDev.Tasks.Core.csproj
index 964dc112907c..e68b4761d883 100644
--- a/msbuild/Xamarin.MacDev.Tasks.Core/Xamarin.MacDev.Tasks.Core.csproj
+++ b/msbuild/Xamarin.MacDev.Tasks.Core/Xamarin.MacDev.Tasks.Core.csproj
@@ -51,9 +51,9 @@
     </ProjectReference>
   </ItemGroup>
   <ItemGroup>
-    <!-- XBuild does not define the MSBuildRuntimeVersion property. -->
-    <Compile Include="MsBuildTasks\MoveTaskBase.cs" Condition="'$(MSBuildRuntimeVersion)' != ''" />
-    <Compile Include="MsBuildTasks\XBuildMoveTaskBase.cs" Condition="'$(MSBuildRuntimeVersion)' == ''" />
+    <!-- Mono has a different implementation of the Move task, so when building on a Mac we need to include XBuildMoveTaskBase.cs -->
+    <Compile Include="MsBuildTasks\MoveTaskBase.cs" Condition="'$(OS)' == 'Windows_NT'" />
+    <Compile Include="MsBuildTasks\XBuildMoveTaskBase.cs" Condition="'$(OS)' != 'Windows_NT'" />
   </ItemGroup>
   <ItemGroup>
     <Compile Include="MsBuildTasks\CopyBase.cs" />