1 files changed, 4 insertions, 1 deletions
diff --git a/error.c b/error.c
index b58f0f76d5..217740f9d9 100644
--- a/error.c
+++ b/error.c
@@ -522,9 +522,12 @@ static VALUE
 exc_to_s(VALUE exc)
 {
     VALUE mesg = rb_attr_get(exc, rb_intern("mesg"));
+    VALUE r = Qnil;
 
     if (NIL_P(mesg)) return rb_class_name(CLASS_OF(exc));
-    return rb_String(mesg);
+    r = rb_String(mesg);
+    OBJ_INFECT(r, exc);
+    return r;
 }
 
 /*