src/jdk.compiler/share/classes/com/sun/tools/javac/code/Lint.java

@@ -116,10 +116,11 @@
 
             Source source = Source.instance(context);
             if (source.compareTo(Source.JDK1_9) >= 0) {
                 values.add(LintCategory.DEP_ANN);
             }
+            values.add(LintCategory.MODULE);
             values.add(LintCategory.REMOVAL);
         }
 
         // Look for specific overrides
         for (LintCategory lc : LintCategory.values()) {

@@ -203,10 +204,15 @@
          * Warn about finally clauses that do not terminate normally.
          */
         FINALLY("finally"),
 
         /**
+         * Warn about module system related issues.
+         */
+        MODULE("module"),
+
+        /**
          * Warn about issues relating to use of command line options
          */
         OPTIONS("options"),
 
         /**