diff --git a/scripts/wt-mode.el b/scripts/wt-mode.el
index caf9679..58f9633 100644
--- a/scripts/wt-mode.el
+++ b/scripts/wt-mode.el
@@ -25,7 +25,7 @@
 ;;   echo $(webrunner -h | sed -n 's,  COMMAND: ,,p') | sed 's, ,\\\\|,g'
 (defconst wt-font-lock-keywords
   (list
-   '("^ *\\(ca-certificate\\|call\\|case\\|check\\|clear-cookies\\|click\\|clicktype\\|client-certificate\\|do\\|download\\|echo\\|execute\\|exists\\|exit\\|expect\\|fail\\|for\\|function\\|if\\|ignoreto\\|include\\|label\\|load\\|not\\|offline-storage-path\\|open\\|screenshot\\|set\\|setvalue\\|sleep\\|testcase\\|testsuite\\|timeout\\|unset\\|upload\\) " . font-lock-builtin-face)
+   '("^ *\\(auth\\|ca-certificate\\|call\\|case\\|check\\|clear-cookies\\|click\\|clicktype\\|client-certificate\\|do\\|download\\|echo\\|execute\\|exists\\|exit\\|expect\\|fail\\|for\\|function\\|if\\|ignoreto\\|include\\|label\\|load\\|not\\|offline-storage-path\\|open\\|screenshot\\|set\\|setvalue\\|sleep\\|testcase\\|testsuite\\|timeout\\|unset\\|upload\\) " . font-lock-builtin-face)
    '("^ *#.*$" . font-lock-comment-face))
   "Highlighting expressions for Webtester")
 
diff --git a/src/editor.hxx b/src/editor.hxx
index 4baaac4..d6dd619 100644
--- a/src/editor.hxx
+++ b/src/editor.hxx
@@ -6,6 +6,38 @@
 #include <QPainter>
 #include <QTextBlock>
 #include <QResizeEvent>
+#include <QSyntaxHighlighter>
+#include <QRegularExpression>
+#include <QRegularExpressionMatch>
+
+class Highlighter: public QSyntaxHighlighter {
+    Q_OBJECT;
+  public:
+    Highlighter(QTextDocument *parent): QSyntaxHighlighter(parent) {
+      QString commands="auth|ca-certificate|call|case|check|clear-cookies|click|clicktype|client-certificate|do|download|echo|execute|exists|exit|expect|fail|for|function|if|ignoreto|include|label|load|not|offline-storage-path|open|screenshot|set|setvalue|sleep|testcase|testsuite|timeout|unset|upload";
+      _expressions<<Expression("^ *("+commands+")\\b").weight(QFont::Bold).fg(Qt::darkBlue)
+                  <<Expression("^ *#.*$").weight(QFont::Bold).fg(Qt::black);
+    }
+  protected:
+    void highlightBlock(const QString &text) {
+      for (auto e: _expressions) {
+        auto m(e.re.match(text));
+        for (int i(0); i<=m.lastCapturedIndex(); ++i) {
+          setFormat(m.capturedStart(i), m.capturedLength(i), e.fmt);
+        }
+      }
+    }
+  private:
+    struct Expression {
+        Expression(QString s): re(s) {}
+        Expression(QString s, QTextCharFormat f): re(s), fmt(f) {}
+        Expression& weight(int w) {fmt.setFontWeight(w); return *this;}
+        Expression& fg(const QBrush& b) {fmt.setForeground(b); return *this;}
+        QRegularExpression re;
+        QTextCharFormat fmt;
+    };
+    QList<Expression> _expressions;
+};
 
 class CodeEditor;
 
@@ -23,6 +55,7 @@ class CodeEditor: public QPlainTextEdit {
     Q_OBJECT;
   public:
     CodeEditor(QWidget *parent = 0): QPlainTextEdit(parent) {
+      new Highlighter(document());
       lineNumberArea = new LineNumberArea(this);
       connect(this, SIGNAL(blockCountChanged(int)), this, SLOT(updateLineNumberAreaWidth(int)));
       connect(this, SIGNAL(updateRequest(QRect,int)), this, SLOT(updateLineNumberArea(QRect,int)));