diff --git a/ngx_rtmp_bandwidth_detection_module.c b/ngx_rtmp_bandwidth_detection_module.c
index 7bacdf0..75009d2 100644
--- a/ngx_rtmp_bandwidth_detection_module.c
+++ b/ngx_rtmp_bandwidth_detection_module.c
@@ -234,11 +234,15 @@ ngx_rtmp_bandwidth_detection_start(ngx_rtmp_session_t *s, ngx_rtmp_header_t *h,
     ngx_rtmp_bandwidth_detection_ctx_t              *bw_ctx;
     ngx_rtmp_live_ctx_t                             *lv_ctx;
 
+    static struct {
+        double                  trans;
+    } v;
+
     static ngx_rtmp_amf_elt_t   in_elts[] = {
 
         { NGX_RTMP_AMF_NUMBER,
           ngx_null_string,
-          "checkBandwidth", 0 },
+          &v.trans, 0 },
 
     };
 
diff --git a/ngx_rtmp_send.c b/ngx_rtmp_send.c
index 7087a63..64390d5 100644
--- a/ngx_rtmp_send.c
+++ b/ngx_rtmp_send.c
@@ -1024,7 +1024,10 @@ ngx_rtmp_create_bwcheck(ngx_rtmp_session_t *s, u_char *payload)
           sizeof(out_inf) },
     };
 
-    out_inf[0].data = payload;
+    if (payload != NULL) {
+        out_inf[0].data = payload;
+        out_inf[0].len = ngx_strlen(payload);
+    }
     trans = NGX_RTMP_BANDWIDTH_DETECTION_BWCHECK_TRANS;
 
     memset(&h, 0, sizeof(h));