1 files changed, 3 insertions, 3 deletions
diff --git a/io.c b/io.c
index 228a2e8129..f21b9211b8 100644
--- a/io.c
+++ b/io.c
@@ -7275,9 +7275,9 @@ static void
 must_respond_to(ID mid, VALUE val, ID id)
 {
     if (!rb_respond_to(val, mid)) {
-	rb_raise(rb_eTypeError, "%s must have %s method, %s given",
-		 rb_id2name(id), rb_id2name(mid),
-		 rb_obj_classname(val));
+	rb_raise(rb_eTypeError, "%"PRIsVALUE" must have %"PRIsVALUE" method, %"PRIsVALUE" given",
+		 rb_id2str(id), rb_id2str(mid),
+		 rb_obj_class(val));
     }
 }