diff --git a/src/network/network_gui.cpp b/src/network/network_gui.cpp
--- a/src/network/network_gui.cpp
+++ b/src/network/network_gui.cpp
@@ -117,7 +117,7 @@ public:
 		*lastof(this->visible) = true;
 	}
 
-	void SetupSmallestSize(Window *w, bool init_array)
+	void SetupSmallestSize(Window *w, bool init_array) override
 	{
 		/* Oh yeah, we ought to be findable! */
 		w->nested_array[WID_NG_HEADER] = this;
@@ -143,7 +143,7 @@ public:
 		this->smallest_x = this->head->smallest_x + this->tail->smallest_x; // First and last are always shown, rest not
 	}
 
-	void AssignSizePosition(SizingType sizing, uint x, uint y, uint given_width, uint given_height, bool rtl)
+	void AssignSizePosition(SizingType sizing, uint x, uint y, uint given_width, uint given_height, bool rtl) override
 	{
 		assert(given_width >= this->smallest_x && given_height >= this->smallest_y);
 
@@ -183,7 +183,7 @@ public:
 		}
 	}
 
-	/* virtual */ void Draw(const Window *w)
+	void Draw(const Window *w) override
 	{
 		int i = 0;
 		for (NWidgetBase *child_wid = this->head; child_wid != NULL; child_wid = child_wid->next) {
@@ -193,7 +193,7 @@ public:
 		}
 	}
 
-	/* virtual */ NWidgetCore *GetWidgetFromPos(int x, int y)
+	NWidgetCore *GetWidgetFromPos(int x, int y) override
 	{
 		if (!IsInsideBS(x, this->pos_x, this->current_x) || !IsInsideBS(y, this->pos_y, this->current_y)) return NULL;