diff --git a/src/ai/ai_gui.cpp b/src/ai/ai_gui.cpp
--- a/src/ai/ai_gui.cpp
+++ b/src/ai/ai_gui.cpp
@@ -646,7 +646,7 @@ struct ScriptTextfileWindow : public Tex
 		this->LoadTextfile(textfile, (slot == OWNER_DEITY) ? GAME_DIR : AI_DIR);
 	}
 
-	/* virtual */ void SetStringParameters(int widget) const
+	void SetStringParameters(int widget) const override
 	{
 		if (widget == WID_TF_CAPTION) {
 			SetDParam(0, (slot == OWNER_DEITY) ? STR_CONTENT_TYPE_GAME_SCRIPT : STR_CONTENT_TYPE_AI);