diff --git a/modules/module-default-nodes-api.c b/modules/module-default-nodes-api.c
index 2a04533c..aaba0d8d 100644
--- a/modules/module-default-nodes-api.c
+++ b/modules/module-default-nodes-api.c
@@ -7,6 +7,7 @@
  */
 
 #include <wp/wp.h>
+#include <spa/utils/defs.h>
 #include <pipewire/keys.h>
 #include "module-default-nodes/common.h"
 
@@ -77,12 +78,15 @@ on_metadata_changed (WpMetadata *m, guint32 subject,
     return;
 
   for (gint i = 0; i < N_DEFAULT_NODES; i++) {
-    gchar name[1024];
     if (!g_strcmp0 (key, DEFAULT_KEY[i])) {
       g_clear_pointer (&self->defaults[i].value, g_free);
-      if (value && !g_strcmp0 (type, "Spa:String:JSON") &&
-          json_object_find (value, "name", name, sizeof(name)) == 0)
-        self->defaults[i].value = g_strdup (name);
+
+      if (value && !g_strcmp0 (type, "Spa:String:JSON")) {
+        g_autoptr (WpSpaJson) json = wp_spa_json_new_from_string (value);
+        g_autofree gchar *name = NULL;
+        if (wp_spa_json_object_get (json, "name", "s", &name, NULL))
+          self->defaults[i].value = g_strdup (name);
+      }
 
       wp_debug_object (m, "changed '%s' -> '%s'", key,
           self->defaults[i].value);
@@ -91,12 +95,17 @@ on_metadata_changed (WpMetadata *m, guint32 subject,
       break;
     } else if (!g_strcmp0 (key, DEFAULT_CONFIG_KEY[i])) {
       g_clear_pointer (&self->defaults[i].config_value, g_free);
-      if (value && !g_strcmp0 (type, "Spa:String:JSON") &&
-          json_object_find (value, "name", name, sizeof(name)) == 0)
-        self->defaults[i].config_value = g_strdup (name);
+
+      if (value && !g_strcmp0 (type, "Spa:String:JSON")) {
+        g_autoptr (WpSpaJson) json = wp_spa_json_new_from_string (value);
+        g_autofree gchar *name = NULL;
+        if (wp_spa_json_object_get (json, "name", "s", &name, NULL))
+          self->defaults[i].config_value = g_strdup (name);
+      }
 
       wp_debug_object (m, "changed '%s' -> '%s'", key,
           self->defaults[i].config_value);
+      break;
     }
   }
 }
diff --git a/modules/module-default-nodes.c b/modules/module-default-nodes.c
index 7ea0ad8f..674870a9 100644
--- a/modules/module-default-nodes.c
+++ b/modules/module-default-nodes.c
@@ -291,7 +291,6 @@ reevaluate_default_node (WpDefaultNodes * self, WpMetadata *m, gint node_t)
 {
   WpNode *node = NULL;
   const gchar *node_name = NULL;
-  gchar buf[1024];
 
   node = find_best_node (self, node_t);
   if (node)
@@ -302,14 +301,17 @@ reevaluate_default_node (WpDefaultNodes * self, WpMetadata *m, gint node_t)
   if (node && node_name &&
       g_strcmp0 (node_name, self->defaults[node_t].value) != 0)
   {
+    g_autoptr (WpSpaJson) json = NULL;
+
     g_free (self->defaults[node_t].value);
     self->defaults[node_t].value = g_strdup (node_name);
 
     wp_info_object (self, "set default node for %s: %s",
         NODE_TYPE_STR[node_t], node_name);
 
-    g_snprintf (buf, sizeof(buf), "{ \"name\": \"%s\" }", node_name);
-    wp_metadata_set (m, 0, DEFAULT_KEY[node_t], "Spa:String:JSON", buf);
+    json = wp_spa_json_new_object ("name", "s", node_name, NULL);
+    wp_metadata_set (m, 0, DEFAULT_KEY[node_t], "Spa:String:JSON",
+        wp_spa_json_get_data (json));
   } else if (!node && self->defaults[node_t].value) {
     g_clear_pointer (&self->defaults[node_t].value, g_free);
     wp_info_object (self, "unset default node for %s", NODE_TYPE_STR[node_t]);
@@ -490,7 +492,6 @@ on_metadata_changed (WpMetadata *m, guint32 subject,
 {
   WpDefaultNodes * self = WP_DEFAULT_NODES (d);
   gint node_t = -1;
-  gchar name[1024];
 
   if (subject == 0) {
     for (gint i = 0; i < N_DEFAULT_NODES; i++) {
@@ -504,10 +505,11 @@ on_metadata_changed (WpMetadata *m, guint32 subject,
   if (node_t != -1) {
     g_clear_pointer (&self->defaults[node_t].config_value, g_free);
 
-    if (value && !g_strcmp0 (type, "Spa:String:JSON") &&
-        json_object_find (value, "name", name, sizeof(name)) == 0)
-    {
-      self->defaults[node_t].config_value = g_strdup (name);
+    if (value && !g_strcmp0 (type, "Spa:String:JSON")) {
+      g_autoptr (WpSpaJson) json = wp_spa_json_new_from_string (value);
+      g_autofree gchar *name = NULL;
+      if (wp_spa_json_object_get (json, "name", "s", &name, NULL))
+        self->defaults[node_t].config_value = g_strdup (name);
     }
 
     wp_debug_object (m, "changed '%s' -> '%s'", key,
@@ -540,12 +542,11 @@ on_metadata_added (WpObjectManager *om, WpMetadata *metadata, gpointer d)
   g_return_if_fail (core);
 
   for (gint i = 0; i < N_DEFAULT_NODES; i++) {
-    gchar buf[1024];
     if (self->defaults[i].config_value) {
-      g_snprintf (buf, sizeof(buf), "{ \"name\": \"%s\" }",
-          self->defaults[i].config_value);
+      g_autoptr (WpSpaJson) json = wp_spa_json_new_object (
+          "name", "s", self->defaults[i].config_value, NULL);
       wp_metadata_set (metadata, 0, DEFAULT_CONFIG_KEY[i], "Spa:String:JSON",
-          buf);
+          wp_spa_json_get_data (json));
     }
   }
 
diff --git a/modules/module-default-nodes/common.h b/modules/module-default-nodes/common.h
index d9338326..e3ff1df1 100644
--- a/modules/module-default-nodes/common.h
+++ b/modules/module-default-nodes/common.h
@@ -6,10 +6,6 @@
  * SPDX-License-Identifier: MIT
  */
 
-#include <glib.h>
-#include <errno.h>
-#include <spa/utils/json.h>
-
 enum {
   AUDIO_SINK,
   AUDIO_SOURCE,
@@ -34,27 +30,3 @@ static const gchar * DEFAULT_CONFIG_KEY[N_DEFAULT_NODES] = {
   [AUDIO_SOURCE] = "default.configured.audio.source",
   [VIDEO_SOURCE] = "default.configured.video.source",
 };
-
-static int
-json_object_find (const char *obj, const char *key, char *value, size_t len)
-{
-  struct spa_json it[2];
-  const char *v;
-  char k[128];
-
-  spa_json_init(&it[0], obj, strlen(obj));
-  if (spa_json_enter_object(&it[0], &it[1]) <= 0)
-    return -EINVAL;
-
-  while (spa_json_get_string(&it[1], k, sizeof(k)) > 0) {
-    if (strcmp(k, key) == 0) {
-      if (spa_json_get_string(&it[1], value, len) <= 0)
-        continue;
-      return 0;
-    } else {
-      if (spa_json_next(&it[1], &v) <= 0)
-        break;
-    }
-  }
-  return -ENOENT;
-}