diff --git a/ui/main.c b/ui/main.c
index a29111e..c5eef0f 100644
--- a/ui/main.c
+++ b/ui/main.c
@@ -38,6 +38,7 @@
 #include "reader.h"
 #include "output.h"
 #include "simio.h"
+#include "sockets.h"

 #include "sim.h"
 #include "bsl.h"