diff --git a/src/plugins/texteditor/highlighter.cpp b/src/plugins/texteditor/highlighter.cpp
index 19f0656a152..e0790875200 100644
--- a/src/plugins/texteditor/highlighter.cpp
+++ b/src/plugins/texteditor/highlighter.cpp
@@ -302,8 +302,10 @@ static bool isClosingParenthesis(QChar c)
 
 void Highlighter::highlightBlock(const QString &text)
 {
-    if (!definition().isValid())
+    if (!definition().isValid()) {
+        formatSpaces(text);
         return;
+    }
     QTextBlock block = currentBlock();
     KSyntaxHighlighting::State state;
     TextDocumentLayout::setBraceDepth(block, TextDocumentLayout::braceDepth(block.previous()));