--- a/test/langtools/tools/javac/lib/DPrinter.java	Tue May 29 12:52:08 2018 +0200
+++ b/test/langtools/tools/javac/lib/DPrinter.java	Tue May 29 13:17:03 2018 +0200
@@ -81,6 +81,7 @@
 import com.sun.tools.javac.util.Assert;
 import com.sun.tools.javac.util.Context;
 import com.sun.tools.javac.util.Convert;
+import com.sun.tools.javac.util.ListBuffer;
 import com.sun.tools.javac.util.Log;
 
 
@@ -405,7 +406,7 @@
             printScope("origin",
                     (Scope) getField(scope, scope.getClass(), "origin"), Details.FULL);
         } else if (scope instanceof CompoundScope) {
-            printList("delegates", (List<?>) getField(scope, CompoundScope.class, "subScopes"));
+            printList("delegates", ((ListBuffer<?>) getField(scope, CompoundScope.class, "subScopes")).toList());
         } else {
             for (Symbol sym : scope.getSymbols()) {
                 printSymbol(sym.name.toString(), sym, Details.SUMMARY);