1 files changed, 1 insertions, 1 deletions

diff --git a/io.c b/io.c
index 09c34f32f1..3a6056f951 100644
--- a/io.c
+++ b/io.c
@@ -3616,7 +3616,7 @@ rb_io_modenum_flags(int mode)
     return flags;
 }
 
-int
+static int
 rb_io_flags_modenum(int flags)
 {
     int mode = 0;