diff --git a/src/vlib/trace_funcs.h b/src/vlib/trace_funcs.h
index 9313d41..3ed4768 100644
--- a/src/vlib/trace_funcs.h
+++ b/src/vlib/trace_funcs.h
@@ -125,7 +125,7 @@
   vlib_trace_main_t *tm = &vm->trace_main;
   u32 trace_index = vlib_buffer_get_trace_index (b);
   vlib_validate_trace (tm, b);
-  _vec_len (tm->trace_buffer_pool[trace_index]) = 0;
+  vec_set_len (tm->trace_buffer_pool[trace_index], 0);
   pool_put_index (tm->trace_buffer_pool, trace_index);
 }