diff --git a/compiler/frontend/src/org/jetbrains/jet/lang/diagnostics/AbstractDiagnosticFactory.java b/compiler/frontend/src/org/jetbrains/jet/lang/diagnostics/AbstractDiagnosticFactory.java
index 8d6198a8a58..aeebc9f633f 100644
--- a/compiler/frontend/src/org/jetbrains/jet/lang/diagnostics/AbstractDiagnosticFactory.java
+++ b/compiler/frontend/src/org/jetbrains/jet/lang/diagnostics/AbstractDiagnosticFactory.java
@@ -19,7 +19,7 @@ package org.jetbrains.jet.lang.diagnostics;
 /**
  * @author abreslav
  */
-public class AbstractDiagnosticFactory {
+public abstract class AbstractDiagnosticFactory {
 
     private String name = null;