diff --git a/src/http/modules/ngx_http_proxy_module.c b/src/http/modules/ngx_http_proxy_module.c
index a6adc3c..0d80b31 100644
--- a/src/http/modules/ngx_http_proxy_module.c
+++ b/src/http/modules/ngx_http_proxy_module.c
@@ -2343,7 +2343,7 @@
 #if (NGX_FREEBSD)
     ssize_t *np = data;
 
-    if (*np >= ngx_freebsd_net_inet_tcp_sendspace) {
+    if ((u_long) *np >= ngx_freebsd_net_inet_tcp_sendspace) {
         ngx_conf_log_error(NGX_LOG_EMERG, cf, 0,
                            "\"proxy_send_lowat\" must be less than %d "
                            "(sysctl net.inet.tcp.sendspace)",