diff --git a/WpfObservableRangeCollection/WpfObservableRangeCollection.csproj b/WpfObservableRangeCollection/WpfObservableRangeCollection.csproj
index 7ce2975..9cfb23b 100644
--- a/WpfObservableRangeCollection/WpfObservableRangeCollection.csproj
+++ b/WpfObservableRangeCollection/WpfObservableRangeCollection.csproj
@@ -12,6 +12,14 @@