diff --git a/lib/src/widgets/raw_editor.dart b/lib/src/widgets/raw_editor.dart
index 87a938bc..5c68111b 100644
--- a/lib/src/widgets/raw_editor.dart
+++ b/lib/src/widgets/raw_editor.dart
@@ -757,6 +757,9 @@ class RawEditorState extends EditorState
         controller.document.queryChild(controller.selection.baseOffset);
 
     KeyEventResult insertTabCharacter() {
+      if (widget.readOnly) {
+        return KeyEventResult.ignored;
+      }
       controller.replaceText(controller.selection.baseOffset, 0, '\t', null);
       _moveCursor(1);
       return KeyEventResult.handled;