diff --git a/net/9p/protocol.c b/net/9p/protocol.c
index 9ee48cb3017..3d33ecf1332 100644
--- a/net/9p/protocol.c
+++ b/net/9p/protocol.c
@@ -368,7 +368,7 @@ p9pdu_vwritef(struct p9_fcall *pdu, int proto_version, const char *fmt,
 				const char *sptr = va_arg(ap, const char *);
 				uint16_t len = 0;
 				if (sptr)
-					len = min_t(uint16_t, strlen(sptr),
+					len = min_t(size_t, strlen(sptr),
 								USHRT_MAX);
 
 				errcode = p9pdu_writef(pdu, proto_version,