diff --git a/gc.c b/gc.c
index 418298a710..0443b313d1 100644
--- a/gc.c
+++ b/gc.c
@@ -1545,9 +1545,11 @@ os_obj_of(VALUE of)
  *     2.2250738585072e-308
  *     Total count: 7
  *
- *  When the process is in multi-Ractor mode (when <code>Ractor.new</code>
- *  has been called within the process at least once), this method yields
- *  Ractor-shareable objects only.
+ *  Due to implementation limitations, this method will not yield
+ *  Ractor-unshareable the process is in multi-Ractor mode (when
+ *  <code>Ractor.new</code> has been called within the process at least once).
+ *  This behavior is not considered ideal.
+ *  See https://bugs.ruby-lang.org/issues/19387 for more information.
  *
  *     a = 12345678987654321 # shareable
  *     b = [].freeze # shareable