diff --git a/tests/Perspex.Base.UnitTests/Perspex.Base.UnitTests.csproj b/tests/Perspex.Base.UnitTests/Perspex.Base.UnitTests.csproj
index de667b5823..85bb146259 100644
--- a/tests/Perspex.Base.UnitTests/Perspex.Base.UnitTests.csproj
+++ b/tests/Perspex.Base.UnitTests/Perspex.Base.UnitTests.csproj
@@ -79,6 +79,7 @@
     <Compile Include="Collections\CollectionChangedTracker.cs" />
     <Compile Include="Collections\PerspexDictionaryTests.cs" />
     <Compile Include="Collections\PerspexListTests.cs" />
+    <Compile Include="Collections\PropertyChangedTracker.cs" />
     <Compile Include="GlobalSuppressions.cs" />
     <Compile Include="PerspexObjectTests_GetObservable.cs" />
     <Compile Include="PerspexObjectTests_Validation.cs" />