diff --git a/src/plugins/cppeditor/cppeditor.cpp b/src/plugins/cppeditor/cppeditor.cpp
index e490c4fbe33..bd376854caf 100644
--- a/src/plugins/cppeditor/cppeditor.cpp
+++ b/src/plugins/cppeditor/cppeditor.cpp
@@ -1202,6 +1202,9 @@ void CPPEditorWidget::finishHighlightSymbolUsages()
     if (m_highlighter.isCanceled())
         return; // aborted
 
+    else if (m_lastSemanticInfo.doc.isNull())
+        return;
+
     TextEditor::SyntaxHighlighter *highlighter = baseTextDocument()->syntaxHighlighter();
     QTC_ASSERT(highlighter, return);