From ea95ea8295ecfe43011ff1997cfd6024996c5418 Mon Sep 17 00:00:00 2001
From: gabime <gmelman1@gmail.com>
Date: Fri, 16 Mar 2018 17:20:56 +0200
Subject: [PATCH] Fix potential issue #660

---
 include/spdlog/fmt/ostr.h | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/include/spdlog/fmt/ostr.h b/include/spdlog/fmt/ostr.h
index cf4c32c5..9902898f 100644
--- a/include/spdlog/fmt/ostr.h
+++ b/include/spdlog/fmt/ostr.h
@@ -4,10 +4,13 @@
 //
 
 #pragma once
-
-// include external or bundled copy of fmtlib's ostream support
+//
+// include bundled or external copy of fmtlib's ostream support
 //
 #if !defined(SPDLOG_FMT_EXTERNAL)
+#ifndef FMT_HEADER_ONLY
+#define FMT_HEADER_ONLY
+#endif
 #include "bundled/ostream.h"
 #include "fmt.h"
 #else