1 files changed, 8 insertions, 0 deletions
diff --git a/ext/zlib/zlib.c b/ext/zlib/zlib.c
index 42c2c75f92..be88118ae6 100644
--- a/ext/zlib/zlib.c
+++ b/ext/zlib/zlib.c
@@ -10,6 +10,7 @@
 #include <zlib.h>
 #include <time.h>
 #include <ruby/io.h>
+#include <fcntl.h>
 
 #ifdef HAVE_VALGRIND_MEMCHECK_H
 # include <valgrind/memcheck.h>
@@ -3412,6 +3413,13 @@ rb_gzreader_initialize(int argc, VALUE *argv, VALUE obj)
 
     Data_Get_Struct(obj, struct gzfile, gz);
     rb_scan_args(argc, argv, "1:", &io, &opt);
+#ifdef O_BINARY
+    if (BUILTIN_TYPE(io) == T_FILE) {
+        rb_io_t *fptr;
+        GetOpenFile(io, fptr);
+        setmode(fptr->fd, O_BINARY);
+    }
+#endif
 
     /* this is undocumented feature of zlib */
     err = inflateInit2(&gz->z.stream, -MAX_WBITS);