diff --git a/src/coordinates.h b/src/coordinates.h
index 02221f38..6fc09983 100644
--- a/src/coordinates.h
+++ b/src/coordinates.h
@@ -22,8 +22,8 @@ public:
 	bool isNull() const
 	  {return std::isnan(_lon) && std::isnan(_lat);}
 	bool isValid() const
-	  {return (!std::isnan(_lon) && !std::isnan(_lat)
-		&& _lon >= -180.0 && _lon <= 180.0 && _lat >= -90.0 && _lat <= 90.0);}
+	  {return (_lon >= -180.0 && _lon <= 180.0
+	    && _lat >= -90.0 && _lat <= 90.0);}
 
 	qreal distanceTo(const Coordinates &c) const;
 	QPair<Coordinates, Coordinates> boundingRect(qreal distance) const;
diff --git a/src/rectc.h b/src/rectc.h
index c1d87b1e..f14b939d 100644
--- a/src/rectc.h
+++ b/src/rectc.h
@@ -15,7 +15,7 @@ public:
 	bool isNull() const
 	  {return _tl.isNull() && _br.isNull();}
 	bool isValid() const
-	  {return !(_tl.isNull() || _br.isNull() || _tl == _br);}
+	  {return (_tl.isValid() && _br.isValid() && _tl != _br);}
 
 	Coordinates topLeft() const {return _tl;}
 	Coordinates bottomRight() const {return _br;}