--- a/src/java.base/share/classes/jdk/internal/module/SystemModuleFinders.java	Tue Aug 07 13:51:30 2018 -0700
+++ b/src/java.base/share/classes/jdk/internal/module/SystemModuleFinders.java	Tue Aug 07 23:08:52 2018 +0200
@@ -282,8 +282,8 @@
 
         SystemModuleFinder(Set<ModuleReference> mrefs,
                            Map<String, ModuleReference> nameToModule) {
-            this.mrefs = Collections.unmodifiableSet(mrefs);
-            this.nameToModule = Collections.unmodifiableMap(nameToModule);
+            this.mrefs = Set.copyOf(mrefs);
+            this.nameToModule = Map.copyOf(nameToModule);
         }
 
         @Override
@@ -353,7 +353,7 @@
                 }
             }
         }
-        return (nameToHash != null) ? nameToHash : Collections.emptyMap();
+        return (nameToHash != null) ? nameToHash : Map.of();
     }
 
     /**