diff --git a/csharp/src/Google.Protobuf.Test/Google.Protobuf.Test.csproj b/csharp/src/Google.Protobuf.Test/Google.Protobuf.Test.csproj
index 20ae8e48..4f37c5e2 100644
--- a/csharp/src/Google.Protobuf.Test/Google.Protobuf.Test.csproj
+++ b/csharp/src/Google.Protobuf.Test/Google.Protobuf.Test.csproj
@@ -55,7 +55,7 @@
     <GenerateSerializationAssemblies>Off</GenerateSerializationAssemblies>
     <Prefer32Bit>false</Prefer32Bit>
     <SignAssembly>True</SignAssembly>
-    <AssemblyOriginatorKeyFile>C:\keys\Google.Protobuf.snk</AssemblyOriginatorKeyFile>
+    <AssemblyOriginatorKeyFile>..\..\keys\Google.Protobuf.snk</AssemblyOriginatorKeyFile>
   </PropertyGroup>
   <ItemGroup>
     <Reference Include="mscorlib" />
diff --git a/csharp/src/Google.Protobuf/Google.Protobuf.csproj b/csharp/src/Google.Protobuf/Google.Protobuf.csproj
index 45ef8c63..ef524baf 100644
--- a/csharp/src/Google.Protobuf/Google.Protobuf.csproj
+++ b/csharp/src/Google.Protobuf/Google.Protobuf.csproj
@@ -64,7 +64,7 @@
     <NoStdLib>true</NoStdLib>
     <GenerateSerializationAssemblies>Off</GenerateSerializationAssemblies>
     <SignAssembly>True</SignAssembly>
-    <AssemblyOriginatorKeyFile>C:\keys\Google.Protobuf.snk</AssemblyOriginatorKeyFile>
+    <AssemblyOriginatorKeyFile>..\..\keys\Google.Protobuf.snk</AssemblyOriginatorKeyFile>
     <TreatWarningsAsErrors>true</TreatWarningsAsErrors>
   </PropertyGroup>
   <ItemGroup>