diff --git a/src/viewport.cpp b/src/viewport.cpp
index 8095d1a1e7..6df6440b99 100644
--- a/src/viewport.cpp
+++ b/src/viewport.cpp
@@ -197,7 +197,7 @@ struct LineSnapPoint : Point {
 typedef SmallVector<LineSnapPoint, 4> LineSnapPoints; ///< Set of snapping points
 
 /** Coordinates of a polyline track made of 2 connected line segments. */
-struct Polyline {
+struct PolylineInfo {
 	Point start;           ///< The point where the first segment starts (as given in LineSnapPoint).
 	Direction first_dir;   ///< Direction of the first line segment.
 	uint first_len;        ///< Length of the first segment - number of track pieces.
@@ -4051,7 +4051,7 @@ Trackdir PointDirToTrackdir(const Point &pt, Direction dir)
 	return ret;
 }
 
-static bool FindPolyline(const Point &pt, const LineSnapPoint &start, Polyline *ret)
+static bool FindPolyline(const Point &pt, const LineSnapPoint &start, PolylineInfo *ret)
 {
 	/* relative coordinats of the mouse point (offset against the snap point) */
 	int x = pt.x - start.x;
@@ -4157,7 +4157,7 @@ static inline uint SqrDist(const Point &a, const Point &b)
 	return (b.x - a.x) * (b.x - a.x) + (b.y - a.y) * (b.y - a.y);
 }
 
-static LineSnapPoint *FindBestPolyline(const Point &pt, LineSnapPoint *snap_points, uint num_points, Polyline *ret)
+static LineSnapPoint *FindBestPolyline(const Point &pt, LineSnapPoint *snap_points, uint num_points, PolylineInfo *ret)
 {
 	/* Find the best polyline (a pair of two lines - the white one and the blue
 	 * one) led from any of saved snap points to the mouse cursor. */
@@ -4166,7 +4166,7 @@ static LineSnapPoint *FindBestPolyline(const Point &pt, LineSnapPoint *snap_poin
 
 	for (int i = 0; i < (int)num_points; i++) {
 		/* try to fit a polyline */
-		Polyline polyline;
+		PolylineInfo polyline;
 		if (!FindPolyline(pt, snap_points[i], &polyline)) continue; // skip non-matching snap points
 		/* check whether we've found a better polyline */
 		if (best_snap_point != NULL) {
@@ -4395,7 +4395,7 @@ static HighLightStyle CalcPolyrailDrawstyle(Point pt, bool dragging)
 	}
 
 	/* find the best track */
-	Polyline line;
+	PolylineInfo line;
 
 	bool lock_snapping = dragging && snap_mode == RSM_SNAP_TO_RAIL;
 	if (!lock_snapping) _current_snap_lock.x = -1;