diff --git a/gc.c b/gc.c
index b71a209998..ff2f308a88 100644
--- a/gc.c
+++ b/gc.c
@@ -82,6 +82,8 @@
 #include <emscripten.h>
 #endif
 
+#undef LIST_HEAD /* ccan/list conflicts with BSD-origin sys/queue.h. */
+
 #include "constant.h"
 #include "debug_counter.h"
 #include "eval_intern.h"