1 files changed, 1 insertions, 1 deletions
diff --git a/io.c b/io.c
index bf10a31d5..7f6ed3c70 100644
--- a/io.c
+++ b/io.c
@@ -7949,7 +7949,7 @@ rb_io_set_encoding(int argc, VALUE *argv, VALUE io)
 }
 
 void
-rb_stdio_set_default_encoding()
+rb_stdio_set_default_encoding(void)
 {
     extern VALUE rb_stdin, rb_stdout, rb_stderr;
     VALUE val = Qnil;