diff --git a/platform/lang-impl/src/com/intellij/codeInsight/daemon/impl/DaemonCodeAnalyzerImpl.java b/platform/lang-impl/src/com/intellij/codeInsight/daemon/impl/DaemonCodeAnalyzerImpl.java
index c5007a6e7427..4cd590aa5898 100644
--- a/platform/lang-impl/src/com/intellij/codeInsight/daemon/impl/DaemonCodeAnalyzerImpl.java
+++ b/platform/lang-impl/src/com/intellij/codeInsight/daemon/impl/DaemonCodeAnalyzerImpl.java
@@ -209,6 +209,7 @@ public class DaemonCodeAnalyzerImpl extends DaemonCodeAnalyzer implements JDOMEx
     TextEditorBackgroundHighlighter highlighter = (TextEditorBackgroundHighlighter)textEditor.getBackgroundHighlighter();
     final List<TextEditorHighlightingPass> passes = highlighter.getPasses(toIgnore);
     HighlightingPass[] array = passes.toArray(new HighlightingPass[passes.size()]);
+    assert array.length != 0: "Highlighting is disabled for the file "+file;
 
     final DaemonProgressIndicator progress = createUpdateProgress();
     progress.setDebug(LOG.isDebugEnabled());