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

*** 116,125 ****
--- 116,126 ----
  
              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()) {
*** 203,212 ****
--- 204,218 ----
           * 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"),
  
          /**