diff --git a/components/audio_client/audio_client.cpp b/components/audio_client/audio_client.cpp
index 3e2f523..bd725f4 100644
--- a/components/audio_client/audio_client.cpp
+++ b/components/audio_client/audio_client.cpp
@@ -295,7 +295,8 @@ bool audio_client_send_pending_request(void)
 {
     if (!s_need_request_image || !s_client) return false;
     s_need_request_image = false;
-    int ret = esp_websocket_client_send_text(s_client, "{\"type\":\"request_image\"}", 23, pdMS_TO_TICKS(1000));
+    static const char REQUEST_IMG_JSON[] = "{\"type\":\"request_image\"}";
+    int ret = esp_websocket_client_send_text(s_client, REQUEST_IMG_JSON, strlen(REQUEST_IMG_JSON), pdMS_TO_TICKS(1000));
     if (ret < 0) {
         ESP_LOGE(TAG, "Failed to send image request: %d", ret);
         return false;