diff --git a/qapi/string-input-visitor.c b/qapi/string-input-visitor.c
index 67a0a4a..b3fdd08 100644
--- a/qapi/string-input-visitor.c
+++ b/qapi/string-input-visitor.c
@@ -16,6 +16,7 @@
 #include "qapi/string-input-visitor.h"
 #include "qapi/visitor-impl.h"
 #include "qapi/qmp/qerror.h"
+#include "qapi/qmp/qnull.h"
 #include "qemu/option.h"
 #include "qemu/queue.h"
 #include "qemu/range.h"