diff --git a/pmd-core/src/main/java/net/sourceforge/pmd/lang/BaseLanguageModule.java b/pmd-core/src/main/java/net/sourceforge/pmd/lang/BaseLanguageModule.java
index 696fcbe974..05cfba2c9f 100644
--- a/pmd-core/src/main/java/net/sourceforge/pmd/lang/BaseLanguageModule.java
+++ b/pmd-core/src/main/java/net/sourceforge/pmd/lang/BaseLanguageModule.java
@@ -51,6 +51,8 @@ public abstract class BaseLanguageModule implements Language {
         }
 
         if (isDefault) {
+            assert defaultVersion == null
+                : "Default version already set to " + defaultVersion + ", cannot set it to " + languageVersion;
             defaultVersion = languageVersion;
         }
     }
diff --git a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/JavaLanguageModule.java b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/JavaLanguageModule.java
index a8052f8f32..c92acd6ea0 100644
--- a/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/JavaLanguageModule.java
+++ b/pmd-java/src/main/java/net/sourceforge/pmd/lang/java/JavaLanguageModule.java
@@ -28,8 +28,10 @@ public class JavaLanguageModule extends BaseLanguageModule {
         addVersion("11", new JavaLanguageHandler(11), false);
         addVersion("12", new JavaLanguageHandler(12), false);
         addVersion("12-preview", new JavaLanguageHandler(12, true), false);
-        addVersion("13", new JavaLanguageHandler(13), true);
+        addVersion("13", new JavaLanguageHandler(13), false);
         addVersion("13-preview", new JavaLanguageHandler(13, true), false);
+        addVersion("14", new JavaLanguageHandler(14), true);
+        addVersion("14-preview", new JavaLanguageHandler(14, true), false);
     }
 
 }