diff --git a/src/plugins/texteditor/generichighlighter/highlightdefinition.cpp b/src/plugins/texteditor/generichighlighter/highlightdefinition.cpp
index 043e2c0eed2..744744a71d6 100644
--- a/src/plugins/texteditor/generichighlighter/highlightdefinition.cpp
+++ b/src/plugins/texteditor/generichighlighter/highlightdefinition.cpp
@@ -55,6 +55,11 @@ HighlightDefinition::HighlightDefinition() :
 HighlightDefinition::~HighlightDefinition()
 {}
 
+bool HighlightDefinition::isValid() const
+{
+    return !m_initialContext.isEmpty();
+}
+
 template <class Element, class Container>
 QSharedPointer<Element> HighlightDefinition::
 GenericHelper::create(const QString &name, Container &container)
diff --git a/src/plugins/texteditor/generichighlighter/highlightdefinition.h b/src/plugins/texteditor/generichighlighter/highlightdefinition.h
index 029eaa7e5b0..b178a2e4760 100644
--- a/src/plugins/texteditor/generichighlighter/highlightdefinition.h
+++ b/src/plugins/texteditor/generichighlighter/highlightdefinition.h
@@ -51,6 +51,8 @@ public:
     HighlightDefinition();
     ~HighlightDefinition();
 
+    bool isValid() const;
+
     QSharedPointer<KeywordList> createKeywordList(const QString &list);
     QSharedPointer<KeywordList> keywordList(const QString &list);
 
diff --git a/src/plugins/texteditor/generichighlighter/highlightdefinitionhandler.cpp b/src/plugins/texteditor/generichighlighter/highlightdefinitionhandler.cpp
index cc123bcf209..a2591322913 100644
--- a/src/plugins/texteditor/generichighlighter/highlightdefinitionhandler.cpp
+++ b/src/plugins/texteditor/generichighlighter/highlightdefinitionhandler.cpp
@@ -449,7 +449,7 @@ void HighlightDefinitionHandler::processIncludeRules(const QSharedPointer<Contex
 
             const QSharedPointer<HighlightDefinition> &externalDefinition =
                 Manager::instance()->definition(id);
-            if (externalDefinition.isNull())
+            if (externalDefinition.isNull() || !externalDefinition->isValid())
                 continue;
 
             sourceContext = externalDefinition->initialContext();
diff --git a/src/plugins/texteditor/plaintexteditor.cpp b/src/plugins/texteditor/plaintexteditor.cpp
index d1abadb6076..90a30a23814 100644
--- a/src/plugins/texteditor/plaintexteditor.cpp
+++ b/src/plugins/texteditor/plaintexteditor.cpp
@@ -180,7 +180,7 @@ void PlainTextEditorWidget::configure(const Core::MimeType &mimeType)
             m_isMissingSyntaxDefinition = false;
             const QSharedPointer<HighlightDefinition> &definition =
                 Manager::instance()->definition(definitionId);
-            if (!definition.isNull()) {
+            if (!definition.isNull() && definition->isValid()) {
                 highlighter->setDefaultContext(definition->initialContext());
 
                 m_commentDefinition.setAfterWhiteSpaces(definition->isCommentAfterWhiteSpaces());