diff --git a/lib/utils/geo_utils.dart b/lib/utils/geo_utils.dart
index 023510678..df0761ef0 100644
--- a/lib/utils/geo_utils.dart
+++ b/lib/utils/geo_utils.dart
@@ -3,8 +3,7 @@ import 'dart:math' as math;
 import 'package:intl/intl.dart';
 import 'package:tuple/tuple.dart';
 
-// adapted from Mike Mitterer's dart-latlong library
-String _decimal2sexagesimal(final double dec) {
+String _decimal2sexagesimal(final double degDecimal) {
   double _round(final double value, {final int decimals = 6}) => (value * math.pow(10, decimals)).round() / math.pow(10, decimals);
 
   List<int> _split(final double value) {
@@ -17,22 +16,15 @@ String _decimal2sexagesimal(final double dec) {
     ];
   }
 
-  final parts = _split(dec);
-  final integerPart = parts[0];
-  final fractionalPart = parts[1];
+  final deg = _split(degDecimal)[0];
+  final minDecimal = (degDecimal.abs() - deg) * 60;
+  final min = _split(minDecimal)[0];
+  final sec = (minDecimal - min) * 60;
 
-  final deg = integerPart;
-  final min = double.parse('0.$fractionalPart') * 60;
-
-  final minParts = _split(min);
-  final minFractionalPart = minParts[1];
-
-  final sec = double.parse('0.$minFractionalPart') * 60;
-
-  return '$deg° ${min.floor()}′ ${_round(sec, decimals: 2).toStringAsFixed(2)}″';
+  return '$deg° $min′ ${_round(sec, decimals: 2).toStringAsFixed(2)}″';
 }
 
-// return coordinates formatted as DMS, e.g. ['41°24′12.2″ N', '2°10′26.5″E']
+// return coordinates formatted as DMS, e.g. ['41° 24′ 12.2″ N', '2° 10′ 26.5″ E']
 List<String> toDMS(Tuple2<double, double> latLng) {
   if (latLng == null) return [];
   final lat = latLng.item1;
diff --git a/test/utils/geo_utils_test.dart b/test/utils/geo_utils_test.dart
new file mode 100644
index 000000000..0057dfb10
--- /dev/null
+++ b/test/utils/geo_utils_test.dart
@@ -0,0 +1,12 @@
+import 'package:aves/utils/geo_utils.dart';
+import 'package:test/test.dart';
+import 'package:tuple/tuple.dart';
+
+void main() {
+  test('Decimal degrees to DMS (sexagesimal)', () {
+    expect(toDMS(Tuple2(37.496667, 127.0275)), ['37° 29′ 48.00″ N', '127° 1′ 39.00″ E']); // Gangnam
+    expect(toDMS(Tuple2(78.9243503, 11.9230465)), ['78° 55′ 27.66″ N', '11° 55′ 22.97″ E']); // Ny-Ålesund
+    expect(toDMS(Tuple2(-38.6965891, 175.9830047)), ['38° 41′ 47.72″ S', '175° 58′ 58.82″ E']); // Taupo
+    expect(toDMS(Tuple2(-64.249391, -56.6556145)), ['64° 14′ 57.81″ S', '56° 39′ 20.21″ W']); // Marambio
+  });
+}