diff --git a/geometry3Sharp.csproj b/geometry3Sharp.csproj
index 1d998af5..5a6d1530 100644
--- a/geometry3Sharp.csproj
+++ b/geometry3Sharp.csproj
@@ -31,6 +31,7 @@
     <ErrorReport>prompt</ErrorReport>
     <WarningLevel>4</WarningLevel>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
+    <PlatformTarget>x64</PlatformTarget>
   </PropertyGroup>
   <ItemGroup>
     <Reference Include="System" />