From c5d14a85ec607553745682b066fe45e4df98d9cc Mon Sep 17 00:00:00 2001
From: Elliot Hesp <elliot.hesp@gmail.com>
Date: Thu, 25 May 2017 10:39:19 +0100
Subject: [PATCH] [pref] Update docs

---
 docs/modules/perf.md | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/docs/modules/perf.md b/docs/modules/perf.md
index 2cddb246..0939226b 100644
--- a/docs/modules/perf.md
+++ b/docs/modules/perf.md
@@ -30,6 +30,8 @@ const trace = firebase.perf().newTrace("test_trace");
 
 ### Trace
 
+!> Once a trace has been started and stopped, you cannot re-start it in the same app lifecycle.
+
 #### start()
 
 Initializes the trace to start tracing performance to relay back to Firebase.