diff --git a/packet.c b/packet.c
index cacc06d..a1034b7 100644
--- a/packet.c
+++ b/packet.c
@@ -58,7 +58,7 @@ static void buf_compress(buffer * dest, buffer * src, unsigned int len);
 void write_packet() {
 
 	ssize_t written;
-#ifdef HAVE_WRITEV
+#if defined(HAVE_WRITEV) && (defined(IOV_MAX) || defined(UIO_MAXIOV))
 	/* 50 is somewhat arbitrary */
 	unsigned int iov_count = 50;
 	struct iovec iov[50];