diff --git a/lib/plat/windows/windows-sockets.c b/lib/plat/windows/windows-sockets.c
index 6bbc066b8..9e8ce2656 100644
--- a/lib/plat/windows/windows-sockets.c
+++ b/lib/plat/windows/windows-sockets.c
@@ -604,7 +604,7 @@ lws_plat_mbedtls_net_send(void *ctx, const uint8_t *buf, size_t len)
 	if (fd < 0)
 		return MBEDTLS_ERR_NET_INVALID_CONTEXT;
 
-	ret = send(fd, buf, (unsigned int)len, 0);
+	ret = send(fd, (const char *)buf, (unsigned int)len, 0);
 	if (ret >= 0)
 		return ret;
 
@@ -629,7 +629,7 @@ lws_plat_mbedtls_net_recv(void *ctx, unsigned char *buf, size_t len)
 	if (fd < 0)
 		return MBEDTLS_ERR_NET_INVALID_CONTEXT;
 
-	ret = (int)recv(fd, buf, (unsigned int)len, 0);
+	ret = (int)recv(fd, (char *)buf, (unsigned int)len, 0);
 	if (ret >= 0)
 		return ret;