diff --git a/WaveshareUARTFingerprintSensor/WaveshareUARTFingerprintSensor.csproj b/WaveshareUARTFingerprintSensor/WaveshareUARTFingerprintSensor.csproj
index 870a979..c51b466 100644
--- a/WaveshareUARTFingerprintSensor/WaveshareUARTFingerprintSensor.csproj
+++ b/WaveshareUARTFingerprintSensor/WaveshareUARTFingerprintSensor.csproj
@@ -62,6 +62,7 @@
   </ItemGroup>
   <ItemGroup>
     <Compile Include="CommandType.cs" />
+    <Compile Include="Exceptions\SensorStateException.cs" />
     <Compile Include="FingerprintSensor.cs" />
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="ResponseType.cs" />