diff --git a/2016/android/Geofence/app/src/main/java/com/esrlabs/geofence/PolygonGeofence.java b/2016/android/Geofence/app/src/main/java/com/esrlabs/geofence/PolygonGeofence.java
index 4e14397..fbc416a 100644
--- a/2016/android/Geofence/app/src/main/java/com/esrlabs/geofence/PolygonGeofence.java
+++ b/2016/android/Geofence/app/src/main/java/com/esrlabs/geofence/PolygonGeofence.java
@@ -22,13 +22,51 @@ public class PolygonGeofence implements Geofence {
      */
     @Override
     public boolean containsLocation(Location location) {
-        int numberOfCorners = polygonPoints.size();
-
-        //adding the first corner at the end so that we can count the edge between last and first corners too
-        List<Location> corners = new ArrayList<Location>(polygonPoints);
-        corners.add(polygonPoints.get(0));
-
-        return false;
+        return pointIsInRegion(location);
     }
 
+    private boolean pointIsInRegion(Location aTestLocation) {
+        boolean inside = false;
+
+        int count = polygonPoints.size();
+        for (int i = 0; i < count; i++) {
+            Location beginOfLineLocation = polygonPoints.get(i);
+            Location endOfLineLocation = polygonPoints.get((i + 1) % count);
+            if (rayCrossesSegment(aTestLocation, beginOfLineLocation, endOfLineLocation)) {
+                inside = !inside;
+            }
+        }
+
+        return inside;
+    }
+
+    private boolean rayCrossesSegment(Location point, Location beginOfLine, Location endOfLine) {
+        double pointX = point.getLongitude();
+        double pointY = point.getLatitude();
+        double beginOfLineX = beginOfLine.getLongitude();
+        double beginOfLineY = beginOfLine.getLatitude();
+        double endOfLineX = endOfLine.getLongitude();
+        double endOfLineY = endOfLine.getLatitude();
+
+        if (beginOfLineY > endOfLineY) {
+            return rayCrossesSegment(point, endOfLine, beginOfLine);
+        }
+
+        if (pointY == beginOfLineY || pointY == endOfLineY) {
+            pointY += 0.00000001;
+        }
+
+        if ( (pointY > endOfLineY || pointY < beginOfLineY) || (pointX > Math.max(beginOfLineX, endOfLineX)) ) {
+            return false;
+        }
+
+        if (pointX < Math.min(beginOfLineX, endOfLineX)) {
+            return true;
+        }
+
+        double red = (pointY - beginOfLineY) / (double) (pointX - beginOfLineX);
+        double blue = (endOfLineY - beginOfLineY) / (double) (endOfLineX - beginOfLineX);
+
+        return (blue >= red);
+    }
 }
diff --git a/2016/android/Geofence/app/src/test/java/com/esrlabs/geofence/PolygonGeofenceTest.java b/2016/android/Geofence/app/src/test/java/com/esrlabs/geofence/PolygonGeofenceTest.java
index c76753e..71a400f 100644
--- a/2016/android/Geofence/app/src/test/java/com/esrlabs/geofence/PolygonGeofenceTest.java
+++ b/2016/android/Geofence/app/src/test/java/com/esrlabs/geofence/PolygonGeofenceTest.java
@@ -19,23 +19,31 @@ import static com.esrlabs.geofence.Utils.location;
 @Config(constants = BuildConfig.class, emulateSdk = 17)
 public class PolygonGeofenceTest extends TestCase {
     // Test polygon defined physically like:
-    // 48.119033, 11.601664         48.119051, 11.601766
+    // 48.119033, 11.601664         48.119051, 11.603766
+    //
+    //              48.118051, 11.600766 -> This doesn't work - the test was defect
+    //
     // 48.117726, 11.602404         48.117758, 11.602543
-    public static final Location testPolygonTopRightCorner = location(NETWORK_PROVIDER, 48.119033, 11.601664);
-    public static final Location testPolygonTopLeftCorner = location(NETWORK_PROVIDER, 48.119051, 11.601966);
-    public static final Location testPolygonBottomRightCorner = location(NETWORK_PROVIDER, 48.116726, 11.602404);
-    public static final Location testPolygonBottomLeftCorner = location(NETWORK_PROVIDER, 48.116758, 11.602743);
+    public static final Location testPolygonTopLeftCorner = location(NETWORK_PROVIDER, 48.119033, 11.601664);
+    public static final Location testPolygonTopRightCorner = location(NETWORK_PROVIDER, 48.119051, 11.603766);
+    public static final Location testPolygonBottomRightCorner = location(NETWORK_PROVIDER, 48.117758, 11.602543);
+    public static final Location testPolygonBottomLeftCorner = location(NETWORK_PROVIDER, 48.117726, 11.602404);
     public static final PolygonGeofence testGeofence = new PolygonGeofence(testPolygonTopRightCorner, testPolygonTopLeftCorner,
             testPolygonBottomRightCorner, testPolygonBottomLeftCorner);
 
     @Test
     public void testContainsLocation() throws Exception {
         assertTrue(testGeofence.containsLocation(someLocationInside()));
+        assertTrue(testGeofence.containsLocation(anotherLocationInside()));
         assertFalse(testGeofence.containsLocation(someLocationOutside()));
     }
 
     private Location someLocationInside() {
-        return location(NETWORK_PROVIDER, testPolygonTopRightCorner.getLatitude() - 0.001, testPolygonTopRightCorner.getLongitude() - 0.001);
+        return location(NETWORK_PROVIDER, testPolygonTopRightCorner.getLatitude() - 0.0001, testPolygonTopRightCorner.getLongitude() - 0.0001);
+    }
+
+    private Location anotherLocationInside() {
+        return location(NETWORK_PROVIDER, 48.118, 11.60245);
     }
 
     private Location someLocationOutside() {