diff --git a/Makefile b/Makefile
index 7c370ea57c..9472ff768c 100644
--- a/Makefile
+++ b/Makefile
@@ -909,6 +909,7 @@ ifeq ($(uname_S),SunOS)
 	NO_MKSTEMPS = YesPlease
 	NO_REGEX = YesPlease
 	NO_FNMATCH_CASEFOLD = YesPlease
+	HAVE_DEV_TTY = YesPlease
 	ifeq ($(uname_R),5.6)
 		SOCKLEN_T = int
 		NO_HSTRERROR = YesPlease