diff --git a/gpxsee.pro b/gpxsee.pro
index 809bb7a6..d0227c07 100644
--- a/gpxsee.pro
+++ b/gpxsee.pro
@@ -151,7 +151,8 @@ SOURCES += src/main.cpp \
     src/tar.cpp \
     src/atlas.cpp \
     src/mercator.cpp \
-    src/transversemercator.cpp
+    src/transversemercator.cpp \
+    src/utm.cpp
 RESOURCES += gpxsee.qrc
 TRANSLATIONS = lang/gpxsee_cs.ts \
     lang/gpxsee_sv.ts
diff --git a/src/offlinemap.cpp b/src/offlinemap.cpp
index 353ca953..223b986b 100644
--- a/src/offlinemap.cpp
+++ b/src/offlinemap.cpp
@@ -128,6 +128,12 @@ int OfflineMap::parseMapFile(QIODevice &device, QList<ReferencePoint> &points,
 bool OfflineMap::createProjection(const QString &projection,
   const ProjectionSetup &setup, QList<ReferencePoint> &points)
 {
+	if (points.count() < 2) {
+		qWarning("%s: insufficient number of reference points",
+		  qPrintable(_name));
+		return false;
+	}
+
 	if (projection == "Mercator")
 		_projection = new Mercator();
 	else if (projection == "Transverse Mercator")
@@ -135,9 +141,16 @@ bool OfflineMap::createProjection(const QString &projection,
 		  setup.falseEasting, setup.falseNorthing);
 	else if (projection == "Latitude/Longitude")
 		_projection = new LatLon();
-	else if (projection == "(UTM) Universal Transverse Mercator")
-		_projection = new UTM(setup.zone);
-	else {
+	else if (projection == "(UTM) Universal Transverse Mercator") {
+		if (setup.zone)
+			_projection = new UTM(setup.zone);
+		else if (!points.first().ll.isNull())
+			_projection = new UTM(points.first().ll);
+		else {
+			qWarning("%s: Can not determine UTM zone", qPrintable(_name));
+			return false;
+		}
+	} else {
 		qWarning("%s: %s: unsupported map projection", qPrintable(_name),
 		  qPrintable(projection));
 		return false;
@@ -152,11 +165,7 @@ bool OfflineMap::createProjection(const QString &projection,
 
 bool OfflineMap::computeTransformation(const QList<ReferencePoint> &points)
 {
-	if (points.count() < 2) {
-		qWarning("%s: insufficient number of reference points",
-		  qPrintable(_name));
-		return false;
-	}
+	Q_ASSERT(points.count() >= 2);
 
 	Matrix c(3, 2);
 	c.zeroize();
diff --git a/src/transversemercator.cpp b/src/transversemercator.cpp
index e4235d92..47868d52 100644
--- a/src/transversemercator.cpp
+++ b/src/transversemercator.cpp
@@ -3,6 +3,15 @@
 #include "wgs84.h"
 #include "transversemercator.h"
 
+
+TransverseMercator::TransverseMercator()
+{
+	_centralMeridian = 0;
+	_scale = 1.0;
+	_falseEasting = 0;
+	_falseNorthing = 0;
+}
+
 TransverseMercator::TransverseMercator(double centralMeridian, double scale,
   double falseEasting, double falseNorthing)
 {
diff --git a/src/transversemercator.h b/src/transversemercator.h
index 00fdf74d..4cf4cc19 100644
--- a/src/transversemercator.h
+++ b/src/transversemercator.h
@@ -6,6 +6,7 @@
 class TransverseMercator : public Projection
 {
 public:
+	TransverseMercator();
 	TransverseMercator(double centralMeridian, double scale,
 	  double falseEasting, double falseNorthing);
 
diff --git a/src/utm.h b/src/utm.h
index d7efd122..5a7a3eb5 100644
--- a/src/utm.h
+++ b/src/utm.h
@@ -9,6 +9,7 @@ class UTM : public Projection
 public:
 	UTM(int zone) : _tm((qAbs(zone) - 1)*6 - 180 + 3, 0.9996, 500000,
 	  zone < 0 ? 10000000 : 0) {}
+	UTM(const Coordinates &c);
 
 	virtual QPointF ll2xy(const Coordinates &c) const
 	  {return _tm.ll2xy(c);}