1 files changed, 1 insertions, 1 deletions
diff --git a/io.c b/io.c
index b06016d091..2fba88e088 100644
--- a/io.c
+++ b/io.c
@@ -674,7 +674,7 @@ rb_io_wait_writable(int f)
 }
 
 /* xxx: better way to determine the newline of the platform? */
-#if defined(O_BINARY) && O_BINARY != 0
+#if defined(RUBY_TEST_CRLF_ENVIRONMENT) || defined(O_BINARY) && O_BINARY != 0
 /* Windows */
 # define NEED_NEWLINE_DECODER(fptr) (!(fptr->mode & FMODE_BINMODE))
 # define NEED_NEWLINE_ENCODER(fptr) (!(fptr->mode & FMODE_BINMODE))