diff --git a/Makefile b/Makefile
index 785e313..94be6d1 100644
--- a/Makefile
+++ b/Makefile
@@ -332,7 +332,7 @@
   # We also enable getaddrinfo() which works since solaris 8.
   set_target_defaults = $(call default_opts, \
     USE_POLL USE_TPROXY USE_LIBCRYPT USE_CRYPT_H USE_GETADDRINFO USE_THREAD \
-    USE_OBSOLETE_LINKER USE_EVPORTS)
+    USE_RT USE_OBSOLETE_LINKER USE_EVPORTS)
   TARGET_CFLAGS  = -DFD_SETSIZE=65536 -D_REENTRANT -D_XOPEN_SOURCE=500 -D__EXTENSIONS__
   TARGET_LDFLAGS = -lnsl -lsocket
 endif