1 files changed, 2 insertions, 2 deletions
diff --git a/io.c b/io.c
index 4c9bbcf038..aacccd4e13 100644
--- a/io.c
+++ b/io.c
@@ -1056,9 +1056,9 @@ rb_io_binmode(io)
     return io;
 }
 
-static int
+int
 rb_io_mode_flags(mode)
-    char *mode;
+    const char *mode;
 {
     int flags = 0;