diff --git a/src/tool_binmode.c b/src/tool_binmode.c
index 4afe9a413e43f74b1539c3b972dc4dd71dc8e9c0..51bbb45d2daf0edb994de3a058a7b3de2d8b40e1 100644
--- a/src/tool_binmode.c
+++ b/src/tool_binmode.c
@@ -37,10 +37,12 @@
 
 void set_binmode(FILE *stream)
 {
-#ifdef __HIGHC__
+#ifdef O_BINARY
+#  ifdef __HIGHC__
   _setmode(stream, O_BINARY);
-#else
+#  else
   setmode(fileno(stream), O_BINARY);
+#  endif
 #endif
 }