diff --git a/uppsrc/Core/Core.upp b/uppsrc/Core/Core.upp
index 7a82fd23f..6d50a4029 100644
--- a/uppsrc/Core/Core.upp
+++ b/uppsrc/Core/Core.upp
@@ -63,6 +63,8 @@ file
 	Stream.h,
 	Stream.cpp optimize_speed,
 	BlockStream.cpp optimize_speed,
+	FilterStream.h,
+	FilterStream.cpp,
 	Profile.h,
 	Diag.h,
 	Log.cpp,