diff --git a/lib/librt/Makefile b/lib/librt/Makefile
index 00d8cda009e..62c6b9731a1 100644
--- a/lib/librt/Makefile
+++ b/lib/librt/Makefile
@@ -4,6 +4,7 @@ LIB=rt
 SHLIB_MAJOR= 1
 CFLAGS+=-I${.CURDIR}/../libc/include -I${.CURDIR}
 CFLAGS+=-Winline -Wall -g
+LDADD+=-lpthread
 
 #MAN=	libthr.3