--- old/src/java.base/share/classes/java/util/concurrent/ForkJoinTask.java	2020-07-23 15:02:54.738574191 -0700
+++ new/src/java.base/share/classes/java/util/concurrent/ForkJoinTask.java	2020-07-23 15:02:54.346574191 -0700
@@ -242,6 +242,11 @@
     private static final int SIGNAL   = 1 << 16; // true if joiner waiting
     private static final int SMASK    = 0xffff;  // short bits for tags
 
+    /**
+     * Constructor for subclasses to call.
+     */
+    public ForkJoinTask() {}
+
     static boolean isExceptionalStatus(int s) {  // needed by subclasses
         return (s & THROWN) != 0;
     }