diff --git a/src/viewport.cpp b/src/viewport.cpp
index 6a3715a0ea..b18c4fd7de 100644
--- a/src/viewport.cpp
+++ b/src/viewport.cpp
@@ -173,7 +173,7 @@ void DeleteWindowViewport(Window *w)
  * @param height Height of the viewport
  * @param follow_flags Flags controlling the viewport.
  *        - If bit 31 is set, the lower 16 bits are the vehicle that the viewport should follow.
- *        - If bit 31 is clear, it is a tile position.
+ *        - If bit 31 is clear, it is a #TileIndex.
  * @param zoom Zoomlevel to display
  */
 void InitializeWindowViewport(Window *w, int x, int y,
diff --git a/src/widget.cpp b/src/widget.cpp
index fe0f2ce4bb..df89438ca9 100644
--- a/src/widget.cpp
+++ b/src/widget.cpp
@@ -1573,7 +1573,7 @@ void NWidgetViewport::Draw(const Window *w)
 /**
  * Initialize the viewport of the window.
  * @param w            Window owning the viewport.
- * @param follow_flags Type of viewport, see #InitializeViewport().
+ * @param follow_flags Type of viewport, see #InitializeWindowViewport().
  * @param zoom         Zoom level.
  */
 void NWidgetViewport::InitializeViewport(Window *w, uint32 follow_flags, ZoomLevel zoom)