diff --git a/CommonProject.properties b/CommonProject.properties
index 4e2d4c46e..08e2f7b62 100644
--- a/CommonProject.properties
+++ b/CommonProject.properties
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8" ?>
-<Project ToolsVersion="4.0" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+<Project ToolsVersion="3.5" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <PropertyGroup Condition="'$(Configuration)|$(Platform)' == 'Debug|x86'">
     <DebugSymbols>true</DebugSymbols>
     <OutputPath>bin\Debug\</OutputPath>
diff --git a/GreenshotInterop/GreenshotInterop.csproj b/GreenshotInterop/GreenshotInterop.csproj
index e2a1e7bee..0e22ab292 100644
--- a/GreenshotInterop/GreenshotInterop.csproj
+++ b/GreenshotInterop/GreenshotInterop.csproj
@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
+<Project ToolsVersion="3.5" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <PropertyGroup>
     <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
     <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>