diff --git a/artiq/runtime/liblwip/lwipopts.h b/artiq/runtime/liblwip/lwipopts.h
index d53f76785..1dc945e96 100644
--- a/artiq/runtime/liblwip/lwipopts.h
+++ b/artiq/runtime/liblwip/lwipopts.h
@@ -105,7 +105,7 @@ a lot of data that needs to be copied, this should be set high. */
 
 /* ---------- TCP options ---------- */
 #define LWIP_TCP                1
-#define LWIP_TCP_KEEPALIVE      0
+#define LWIP_TCP_KEEPALIVE      1
 #define TCP_KEEPIDLE_DEFAULT    1250
 #define TCP_KEEPINTVL_DEFAULT   1000
 #define TCP_KEEPCNT_DEFAULT     3