diff --git a/apisix/plugins/zipkin.lua b/apisix/plugins/zipkin.lua
index ab284cefe9fa7..51596d06c3f73 100644
--- a/apisix/plugins/zipkin.lua
+++ b/apisix/plugins/zipkin.lua
@@ -19,6 +19,8 @@ local new_tracer = require("opentracing.tracer").new
 local zipkin_codec = require("apisix.plugins.zipkin.codec")
 local new_random_sampler = require("apisix.plugins.zipkin.random_sampler").new
 local new_reporter = require("apisix.plugins.zipkin.reporter").new
+local rand_bytes = require "resty.random".bytes
+local to_hex = require "resty.string".to_hex
 local ngx = ngx
 local ngx_re = require("ngx.re")
 local pairs = pairs
@@ -163,9 +165,9 @@ function _M.rewrite(plugin_conf, ctx)
         -- pass the trace ids even the sample is rejected
         -- see https://github.com/openzipkin/b3-propagation#why-send-
         -- trace-ids-with-a-reject-sampling-decision
-        core.request.set_header(ctx, "x-b3-traceid", trace_id)
-        core.request.set_header(ctx, "x-b3-parentspanid", parent_span_id)
-        core.request.set_header(ctx, "x-b3-spanid", request_span_id)
+        core.request.set_header(ctx, "x-b3-traceid", trace_id or to_hex(rand_bytes(16)))
+        core.request.set_header(ctx, "x-b3-parentspanid", parent_span_id or to_hex(rand_bytes(8)))
+        core.request.set_header(ctx, "x-b3-spanid", request_span_id or to_hex(rand_bytes(8)))
         return
     end