diff --git a/Makefile b/Makefile
index cc2d244b..8df380cc 100644
--- a/Makefile
+++ b/Makefile
@@ -14,7 +14,7 @@ SUBDIRS = inst/pre \
 		cfgfile gtopts \
 		lock sigsync shmem \
 		usrv uclnt statecheck msgfmt \
-		YMisc YError YMem \
+		YMisc YError YMem YOptString \
 		YThread YMutex YEvent YCbContr contr/Y2WayMap contr/YQueue contr/YRingBuffer \
 		YTimeB YStopWatch YStopWatchList YStopWatchQueue YStopWatchThreadList \
 		YOsc \