diff --git a/doc/how_to_build_win.md b/doc/how_to_build_win.md
index 94eaf9e..376e47e 100644
--- a/doc/how_to_build_win.md
+++ b/doc/how_to_build_win.md
@@ -63,13 +63,6 @@ Rename the following files:
   - `$opentoonz/thirdparty/libpng-1.6.21/scripts/pnglibconf.h.prebuilt` to `$opentoonz/thirdparty/libpng-1.6.21/pnglibconf.h`
     - Note that the destination is a different folder for the last file.
 
-Add a guard for snprintf at tif_config.h(50):
-```
-+#if _MSC_VER < 1900
-#define snprintf _snprintf
-+#endif
-```
-
 ## Building
 1. Open `$opentoonz/toonz/build/OpenToonz.sln` and change to `Release`
 2. The output will be in `$opentoonz/toonz/build/Release`
diff --git a/doc/how_to_build_win_ja.md b/doc/how_to_build_win_ja.md
index 493e1f4..5bd2847 100644
--- a/doc/how_to_build_win_ja.md
+++ b/doc/how_to_build_win_ja.md
@@ -57,13 +57,6 @@ Visual Studio 2015 と Qt 5.6 でビルドできることを確認していま�
   - `$opentoonz/thirdparty/tiff-4.0.3/libtiff/tiffconf.vc.h` → `$opentoonz/thirdparty/tiff-4.0.3/libtiff/tiffconf.h`
   - `$opentoonz/thirdparty/libpng-1.6.21/scripts/pnglibconf.h.prebuilt` → `$opentoonz/thirdparty/libpng-1.6.21/pnglibconf.h`
 
-`tif_config.h` の 50 行目あたりに下記の修正を加えます:
-```
-+#if _MSC_VER < 1900
-#define snprintf _snprintf
-+#endif
-```
-
 ## ビルド
 1. `$opentoonz/toonz/build/OpenToonz.sln` を開いて Release 構成を選択してビルドします
 2. `$opentoonz/toonz/build/Release` にファイルが生成されます
diff --git a/thirdparty/tiff-4.0.3/libtiff/tif_config.vc.h b/thirdparty/tiff-4.0.3/libtiff/tif_config.vc.h
index c297cf3..859a606 100644
--- a/thirdparty/tiff-4.0.3/libtiff/tif_config.vc.h
+++ b/thirdparty/tiff-4.0.3/libtiff/tif_config.vc.h
@@ -47,7 +47,9 @@
 /* Set the native cpu bit order */
 #define HOST_FILLORDER FILLORDER_LSB2MSB
 
+#if defined(_MSC_VER) && (_MSC_VER < 1900)
 #define snprintf _snprintf
+#endif
 
 /* Define to 1 if your processor stores words with the most significant byte
    first (like Motorola and SPARC, unlike Intel and VAX). */