1 files changed, 1 insertions, 1 deletions
diff --git a/sprintf.c b/sprintf.c
index afe27c2d63..705d3cece5 100644
--- a/sprintf.c
+++ b/sprintf.c
@@ -1325,7 +1325,7 @@ ruby__sfvwrite(register rb_printf_buffer *fp, register struct __suio *uio)
     return 0;
 }
 
-static char *
+static const char *
 ruby__sfvextra(rb_printf_buffer *fp, size_t valsize, void *valp, long *sz, int sign)
 {
     VALUE value, result = (VALUE)fp->_bf._base;