diff --git a/src/utils.cc b/src/utils.cc
index 87c8704..084456d 100644
--- a/src/utils.cc
+++ b/src/utils.cc
@@ -958,7 +958,7 @@
     os << prefix << "(unwind_backtrace_thread failed for thread " << tid << ")\n";
     return;
   } else if (frame_count == 0) {
-    os << prefix << "(no native stack frames)\n";
+    os << prefix << "(no native stack frames for thread " << tid << ")\n";
     return;
   }