diff --git a/lib/librt/Makefile b/lib/librt/Makefile
index 8b880c41ec44..2c8eb1400fb9 100644
--- a/lib/librt/Makefile
+++ b/lib/librt/Makefile
@@ -1,27 +1,27 @@
 
 .include <src.opts.mk>
 
 PACKAGE=clibs
 LIB=rt
-SHLIBDIR=/lib
+SHLIBDIR?=/lib
 SHLIB_MAJOR= 1
 CFLAGS+=-I${SRCTOP}/lib/libc/include -I${.CURDIR}
 .ifndef NO_THREAD_STACK_UNWIND
 CFLAGS+=-fexceptions
 .endif
 CFLAGS+=-Wall
 LIBADD=	pthread
 
 WARNS?=	2
 
 SRCS+= aio.c mq.c sigev_thread.c timer.c
 
 PRECIOUSLIB=
 
 VERSION_DEF=${SRCTOP}/lib/libc/Versions.def
 SYMBOL_MAPS=${.CURDIR}/Symbol.map
 
 HAS_TESTS=
 SUBDIR.${MK_TESTS}+= tests
 
 .include <bsd.lib.mk>