diff --git a/src/tools/UBGraphicsRuler.cpp b/src/tools/UBGraphicsRuler.cpp
index 046e229b..cd15de78 100644
--- a/src/tools/UBGraphicsRuler.cpp
+++ b/src/tools/UBGraphicsRuler.cpp
@@ -323,6 +323,10 @@ void UBGraphicsRuler::mouseMoveEvent(QGraphicsSceneMouseEvent *event)
 			QPointF delta = event->pos() - event->lastPos();
 			if (rect().width() + delta.x() < sMinLength)
 				delta.setX(sMinLength - rect().width());
+
+            if (rect().width() + delta.x() > sMaxLength)
+                delta.setX(sMaxLength - rect().width());
+
 			setRect(QRectF(rect().topLeft(), QSizeF(rect().width() + delta.x(), rect().height())));
         }
         else
diff --git a/src/tools/UBGraphicsRuler.h b/src/tools/UBGraphicsRuler.h
index d3beca82..fb74dd9d 100644
--- a/src/tools/UBGraphicsRuler.h
+++ b/src/tools/UBGraphicsRuler.h
@@ -90,7 +90,8 @@ class UBGraphicsRuler : public UBAbstractDrawRuler, public QGraphicsRectItem, pu
         // Constants
         static const QRect               sDefaultRect;
 
-		static const int	sMinLength = 150;
+		static const int	sMinLength = 150;   // 3sm
+        static const int	sMaxLength = 35000; // 700sm
 };
 
 #endif /* UBGRAPHICSRULER_H_ */