diff --git a/sys/src/cmd/upas/smtp/smtp.c b/sys/src/cmd/upas/smtp/smtp.c
index 41395899a..37fb5fbd7 100644
--- a/sys/src/cmd/upas/smtp/smtp.c
+++ b/sys/src/cmd/upas/smtp/smtp.c
@@ -328,6 +328,7 @@ wraptls(void)
 	int fd;
 	uchar hash[SHA1dlen];
 
+	goodcerts = nil;
 	err = Giveup;
 	c = mallocz(sizeof(*c), 1);
 	if (c == nil)