diff --git a/io.c b/io.c
index 857c204b4046f8..fbc762ede82a28 100644
--- a/io.c
+++ b/io.c
@@ -12329,8 +12329,8 @@ rb_io_s_binread(int argc, VALUE *argv, VALUE io)
 {
     VALUE offset;
     struct foreach_arg arg;
+    enum rb_io_mode fmode = FMODE_READABLE|FMODE_BINMODE;
     enum {
-        fmode = FMODE_READABLE|FMODE_BINMODE,
         oflags = O_RDONLY
 #ifdef O_BINARY
                 |O_BINARY