diff --git a/configure.ac b/configure.ac
index eee0d23bd..f95d0de57 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1796,6 +1796,7 @@ if test "x$LAUNCHD" = "xauto"; then
 	if test "x$XQUARTZ" = "xyes" ; then
 		LAUNCHD=yes
 	else
+		unset LAUNCHD
 		AC_CHECK_PROG(LAUNCHD, [launchd], [yes], [no])
 	fi
 fi