1 files changed, 2 insertions, 2 deletions
diff --git a/iseq.c b/iseq.c
index 6d8b9e191..680ddd1a0 100644
--- a/iseq.c
+++ b/iseq.c
@@ -116,10 +116,10 @@ iseq_mark(void *ptr)
 }
 
 static size_t
-iseq_memsize(void *ptr)
+iseq_memsize(const void *ptr)
 {
     size_t size = sizeof(rb_iseq_t);
-    rb_iseq_t *iseq;
+    const rb_iseq_t *iseq;
 
     if (ptr) {
 	iseq = ptr;