diff a/src/hotspot/share/gc/shared/cardTable.hpp b/src/hotspot/share/gc/shared/cardTable.hpp
--- a/src/hotspot/share/gc/shared/cardTable.hpp
+++ b/src/hotspot/share/gc/shared/cardTable.hpp
@@ -1,7 +1,7 @@
 /*
- * Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 2020, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.
@@ -103,13 +103,12 @@
 
   enum CardValues {
     clean_card                  = (CardValue)-1,
 
     dirty_card                  =  0,
-    precleaned_card             =  1,
-    last_card                   =  2,
-    CT_MR_BS_last_reserved      =  4
+    last_card                   =  1,
+    CT_MR_BS_last_reserved      =  2
   };
 
   // a word's worth (row) of clean card values
   static const intptr_t clean_card_row = (intptr_t)(-1);
 
@@ -237,11 +236,10 @@
     card_size_in_words          = card_size / sizeof(HeapWord)
   };
 
   static CardValue clean_card_val()          { return clean_card; }
   static CardValue dirty_card_val()          { return dirty_card; }
-  static CardValue precleaned_card_val()     { return precleaned_card; }
   static intptr_t clean_card_row_val()   { return clean_card_row; }
 
   // Card marking array base (adjusted for heap low boundary)
   // This would be the 0th element of _byte_map, if the heap started at 0x0.
   // But since the heap starts at some higher address, this points to somewhere
diff a/src/hotspot/share/gc/shared/cardTableRS.hpp b/src/hotspot/share/gc/shared/cardTableRS.hpp
--- a/src/hotspot/share/gc/shared/cardTableRS.hpp
+++ b/src/hotspot/share/gc/shared/cardTableRS.hpp
@@ -1,7 +1,7 @@
 /*
- * Copyright (c) 2001, 2019, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2020, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.
@@ -148,11 +148,11 @@
 
   // *** Support for parallel card scanning.
 
   // dirty and precleaned are equivalent wrt younger_refs_iter.
   static bool card_is_dirty_wrt_gen_iter(CardValue cv) {
-    return cv == dirty_card || cv == precleaned_card;
+    return cv == dirty_card;
   }
 
   // Returns "true" iff the value "cv" will cause the card containing it
   // to be scanned in the current traversal.  May be overridden by
   // subtypes.