diff --git a/GeoLib/Polyline.h b/GeoLib/Polyline.h
index 4235a8a556f..9cf1a6aac60 100644
--- a/GeoLib/Polyline.h
+++ b/GeoLib/Polyline.h
@@ -51,7 +51,7 @@ enum class Location
 class Polyline : public GeoObject
 {
 public:
-	class SegmentIterator
+	class SegmentIterator final
 	    : public std::iterator<std::forward_iterator_tag, LineSegment>
 	{
 	public:
@@ -60,6 +60,9 @@ class Polyline : public GeoObject
 
 		SegmentIterator(SegmentIterator const& src);
 
+		SegmentIterator() = delete;
+		~SegmentIterator() = default;
+
 		SegmentIterator& operator=(SegmentIterator const& rhs);
 
 		std::size_t getSegmentNumber() const;