diff --git a/include/qapi/visitor.h b/include/qapi/visitor.h
index 33ae28a..2b85c6f 100644
--- a/include/qapi/visitor.h
+++ b/include/qapi/visitor.h
@@ -507,4 +507,16 @@ void visit_type_number(Visitor *v, const char *name, double *obj,
  */
 void visit_type_any(Visitor *v, const char *name, QObject **obj, Error **errp);

+/*
+ * Visit a JSON null value.
+ *
+ * @name expresses the relationship of the null value to its parent
+ * container; see the general description of @name above.
+ *
+ * Unlike all other visit_type_* functions, no obj parameter is
+ * needed; rather, this is a witness that an explicit null value is
+ * expected rather than any other type.
+ */
+void visit_type_null(Visitor *v, const char *name, Error **errp);
+
 #endif
diff --git a/include/qapi/visitor-impl.h b/include/qapi/visitor-impl.h
index d967b18..90bcaec 100644
--- a/include/qapi/visitor-impl.h
+++ b/include/qapi/visitor-impl.h
@@ -86,6 +86,9 @@ struct Visitor
     void (*type_any)(Visitor *v, const char *name, QObject **obj,
                      Error **errp);

+    /* Must be set to visit explicit null values.  */
+    void (*type_null)(Visitor *v, const char *name, Error **errp);
+
     /* Must be set for input visitors, optional otherwise.  The core
      * takes care of the return type in the public interface.  */
     void (*optional)(Visitor *v, const char *name, bool *present);
diff --git a/include/qapi/opts-visitor.h b/include/qapi/opts-visitor.h
index 2002e37..3fcd327 100644
--- a/include/qapi/opts-visitor.h
+++ b/include/qapi/opts-visitor.h
@@ -31,7 +31,7 @@ typedef struct OptsVisitor OptsVisitor;
  * - values above INT64_MAX or LLONG_MAX are rejected.
  *
  * The Opts input visitor does not yet implement support for visiting
- * QAPI alternates, numbers (other than integers), or arbitrary
+ * QAPI alternates, numbers (other than integers), null, or arbitrary
  * QTypes.
  */
 OptsVisitor *opts_visitor_new(const QemuOpts *opts);
diff --git a/include/qapi/string-input-visitor.h b/include/qapi/string-input-visitor.h
index 4c8d1ea..1a34c52 100644
--- a/include/qapi/string-input-visitor.h
+++ b/include/qapi/string-input-visitor.h
@@ -19,7 +19,7 @@ typedef struct StringInputVisitor StringInputVisitor;

 /*
  * The string input visitor does not yet implement support for
- * visiting QAPI structs, alternates, or arbitrary QTypes.
+ * visiting QAPI structs, alternates, null, or arbitrary QTypes.
  */
 StringInputVisitor *string_input_visitor_new(const char *str);
 void string_input_visitor_cleanup(StringInputVisitor *v);
diff --git a/include/qapi/string-output-visitor.h b/include/qapi/string-output-visitor.h
index 094a11e..2564833 100644
--- a/include/qapi/string-output-visitor.h
+++ b/include/qapi/string-output-visitor.h
@@ -19,7 +19,7 @@ typedef struct StringOutputVisitor StringOutputVisitor;

 /*
  * The string output visitor does not yet implement support for
- * visiting QAPI structs, alternates, or arbitrary QTypes.
+ * visiting QAPI structs, alternates, null, or arbitrary QTypes.
  */
 StringOutputVisitor *string_output_visitor_new(bool human);
 void string_output_visitor_cleanup(StringOutputVisitor *v);
diff --git a/qapi/qapi-visit-core.c b/qapi/qapi-visit-core.c
index 1388462..116c627 100644
--- a/qapi/qapi-visit-core.c
+++ b/qapi/qapi-visit-core.c
@@ -218,6 +218,11 @@ void visit_type_any(Visitor *v, const char *name, QObject **obj, Error **errp)
     v->type_any(v, name, obj, errp);
 }

+void visit_type_null(Visitor *v, const char *name, Error **errp)
+{
+    v->type_null(v, name, errp);
+}
+
 static void output_type_enum(Visitor *v, const char *name, int *obj,
                              const char *const strings[], Error **errp)
 {
diff --git a/qapi/qapi-dealloc-visitor.c b/qapi/qapi-dealloc-visitor.c
index c19a459..413d525 100644
--- a/qapi/qapi-dealloc-visitor.c
+++ b/qapi/qapi-dealloc-visitor.c
@@ -163,6 +163,10 @@ static void qapi_dealloc_type_anything(Visitor *v, const char *name,
     }
 }

+static void qapi_dealloc_type_null(Visitor *v, const char *name, Error **errp)
+{
+}
+
 Visitor *qapi_dealloc_get_visitor(QapiDeallocVisitor *v)
 {
     return &v->visitor;
@@ -193,6 +197,7 @@ QapiDeallocVisitor *qapi_dealloc_visitor_new(void)
     v->visitor.type_str = qapi_dealloc_type_str;
     v->visitor.type_number = qapi_dealloc_type_number;
     v->visitor.type_any = qapi_dealloc_type_anything;
+    v->visitor.type_null = qapi_dealloc_type_null;

     QTAILQ_INIT(&v->stack);

