diff --git a/Makefile b/Makefile
index 9fd1f2c6d..200a5f60d 100644
--- a/Makefile
+++ b/Makefile
@@ -314,6 +314,7 @@ ifeq ($(TARGET),solaris)
   USE_LIBCRYPT    = implicit
   USE_CRYPT_H     = implicit
   USE_GETADDRINFO = implicit
+  USE_THREAD      = implicit
 else
 ifeq ($(TARGET),freebsd)
   # This is for FreeBSD