diff --git a/Examples/NBug.Examples.WinForms/NBug.Examples.WinForms.csproj b/Examples/NBug.Examples.WinForms/NBug.Examples.WinForms.csproj
index 8538a42..1ae0125 100644
--- a/Examples/NBug.Examples.WinForms/NBug.Examples.WinForms.csproj
+++ b/Examples/NBug.Examples.WinForms/NBug.Examples.WinForms.csproj
@@ -167,14 +167,14 @@
   </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
   <PropertyGroup>
-    <PostBuildEvent>if $(ConfigurationName)==Release copy "$(TargetPath)" "$(SolutionDir)packages\NBug\tools" /Y
+    <PostBuildEvent Condition="$(OS) == 'WINDOWS_NT'">if $(ConfigurationName)==Release copy "$(TargetPath)" "$(SolutionDir)packages\NBug\tools" /Y
 if $(ConfigurationName)==Release copy "$(TargetDir)$(TargetName).pdb" "$(SolutionDir)packages\NBug\tools" /Y</PostBuildEvent>
   </PropertyGroup>
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
+  <!-- To modify your build process, add your task inside one of the targets below and uncomment it.
        Other similar extension points exist, see Microsoft.Common.targets.
   <Target Name="BeforeBuild">
   </Target>
   <Target Name="AfterBuild">
   </Target>
   -->
-</Project>
\ No newline at end of file
+</Project>
diff --git a/NBug.Configurator/NBug.Configurator.csproj b/NBug.Configurator/NBug.Configurator.csproj
index 341133e..b6ee879 100644
--- a/NBug.Configurator/NBug.Configurator.csproj
+++ b/NBug.Configurator/NBug.Configurator.csproj
@@ -256,14 +256,14 @@
     </PreBuildEvent>
   </PropertyGroup>
   <PropertyGroup>
-    <PostBuildEvent>if $(ConfigurationName)==Release copy "$(TargetPath)" "$(SolutionDir)packages\NBug\tools" /Y
+    <PostBuildEvent Condition="$(OS) == 'WINDOWS_NT'">if $(ConfigurationName)==Release copy "$(TargetPath)" "$(SolutionDir)packages\NBug\tools" /Y
 if $(ConfigurationName)==Release copy "$(TargetDir)$(TargetName).pdb" "$(SolutionDir)packages\NBug\tools" /Y</PostBuildEvent>
   </PropertyGroup>
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
+  <!-- To modify your build process, add your task inside one of the targets below and uncomment it.
        Other similar extension points exist, see Microsoft.Common.targets.
   <Target Name="BeforeBuild">
   </Target>
   <Target Name="AfterBuild">
   </Target>
   -->
-</Project>
\ No newline at end of file
+</Project>
diff --git a/NBug/NBug.csproj b/NBug/NBug.csproj
index ff15459..e32381a 100644
--- a/NBug/NBug.csproj
+++ b/NBug/NBug.csproj
@@ -322,18 +322,18 @@
   <ItemGroup />
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
   <PropertyGroup>
-    <PostBuildEvent>if $(ConfigurationName)==Release copy "$(TargetPath)" "$(SolutionDir)packages\NBug\lib\net40-client" /Y
+    <PostBuildEvent Condition="$(OS) == 'WINDOWS_NT'">if $(ConfigurationName)==Release copy "$(TargetPath)" "$(SolutionDir)packages\NBug\lib\net40-client" /Y
 if $(ConfigurationName)==Release copy "$(TargetDir)$(TargetName).pdb" "$(SolutionDir)packages\NBug\lib\net40-client" /Y
 if $(ConfigurationName)==Release copy "$(TargetDir)$(TargetName).xml" "$(SolutionDir)packages\NBug\lib\net40-client" /Y
 if $(ConfigurationName)==Release copy "$(TargetPath)" "$(SolutionDir)packages\NBug\tools" /Y
 if $(ConfigurationName)==Release copy "$(TargetDir)$(TargetName).pdb" "$(SolutionDir)packages\NBug\tools" /Y</PostBuildEvent>
   </PropertyGroup>
   <Import Project="$(SolutionDir)\.nuget\NuGet.targets" Condition="Exists('$(SolutionDir)\.nuget\NuGet.targets')" />
-  <!-- To modify your build process, add your task inside one of the targets below and uncomment it. 
+  <!-- To modify your build process, add your task inside one of the targets below and uncomment it.
        Other similar extension points exist, see Microsoft.Common.targets.
   <Target Name="BeforeBuild">
   </Target>
   <Target Name="AfterBuild">
   </Target>
   -->
-</Project>
\ No newline at end of file
+</Project>