diff --git a/Makefile b/Makefile
index 9aa6f8ad..0d3038d9 100644
--- a/Makefile
+++ b/Makefile
@@ -17,6 +17,7 @@ SUBDIRS = inst/pre \
 		YMisc YError YMem \
 		YThread YMutex YEvent YCbContr contr/Y2WayMap contr/YQueue \
 		YTimeB YStopWatch YStopWatchList YStopWatchQueue YStopWatchThreadList \
+		YOsc \
 		lib include bin \
 		inst/post