diff --git a/utils/mctp-demux-daemon.c b/utils/mctp-demux-daemon.c
index b7500b5..fc5d583 100644
--- a/utils/mctp-demux-daemon.c
+++ b/utils/mctp-demux-daemon.c
@@ -6,6 +6,7 @@
 #include <err.h>
 #include <errno.h>
 #include <getopt.h>
+#include <limits.h>
 #include <poll.h>
 #include <stdbool.h>
 #include <stdio.h>
@@ -334,7 +335,7 @@
 		goto out_close;
 	}
 
-	if (len > ctx->buf_size) {
+	if ((size_t)len > ctx->buf_size) {
 		void *tmp;
 
 		tmp = realloc(ctx->buf, len);