From 39fa1c2f937cf54e147ab3d0684043bafa32031b Mon Sep 17 00:00:00 2001
From: Mike Dunston <m_dunston@comcast.net>
Date: Fri, 2 Aug 2019 08:29:57 -0700
Subject: [PATCH] Update Print.cpp

#2891
---
 cores/esp32/Print.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/cores/esp32/Print.cpp b/cores/esp32/Print.cpp
index 8c295347f2a..65fa1e9da68 100644
--- a/cores/esp32/Print.cpp
+++ b/cores/esp32/Print.cpp
@@ -52,7 +52,7 @@ size_t Print::printf(const char *format, ...)
     va_list copy;
     va_start(arg, format);
     va_copy(copy, arg);
-    size_t len = vsnprintf(NULL, 0, format, arg);
+    size_t len = vsnprintf(NULL, 0, format, copy);
     va_end(copy);
     if(len >= sizeof(loc_buf)){
         temp = new char[len+1];