diff --git a/misc/json.c b/misc/json.c
index d30450c49d..efe5061521 100644
--- a/misc/json.c
+++ b/misc/json.c
@@ -289,7 +289,7 @@ static void add_indent(bstr *b, int indent)
         bstr_xappend(NULL, b, bstr0(" "));
 }
 
-static int json_append(bstr *b, const struct mpv_node *src, int indent)
+int json_append(bstr *b, const struct mpv_node *src, int indent)
 {
     switch (src->format) {
     case MPV_FORMAT_NONE:
diff --git a/misc/json.h b/misc/json.h
index b99fc36c41..467beb9d26 100644
--- a/misc/json.h
+++ b/misc/json.h
@@ -23,7 +23,10 @@
 
 #define MAX_JSON_DEPTH 50
 
+struct bstr;
+
 int json_parse(void *ta_parent, struct mpv_node *dst, char **src, int max_depth);
+int json_append(struct bstr *b, const struct mpv_node *src, int indent);
 void json_skip_whitespace(char **src);
 int json_write(char **s, struct mpv_node *src);
 int json_write_pretty(char **s, struct mpv_node *src);