1 files changed, 1 insertions, 1 deletions
diff --git a/iseq.c b/iseq.c
index fd148dc1a2..ec9ac5fedd 100644
--- a/iseq.c
+++ b/iseq.c
@@ -675,7 +675,7 @@ iseq_to_a(VALUE self)
 }
 
 int
-rb_iseq_first_lineno(rb_iseq_t *iseq)
+rb_iseq_first_lineno(const rb_iseq_t *iseq)
 {
     return FIX2INT(iseq->line_no);
 }