diff --git a/scripts/fitdump b/scripts/fitdump
index 629f61b..7946be3 100755
--- a/scripts/fitdump
+++ b/scripts/fitdump
@@ -145,9 +145,9 @@ def generate_gpx(records, filename=None):
                 trkpt["speed"] = field_data.value / 3.6
 
         # Add trackpoint
-        if "lat" in trkpt and "lon" in trkpt:
+        if trkpt.get("lat") is not None and trkpt.get("lon") is not None:
             yield '   <trkpt lat="{lat}" lon="{lon}">\n'.format(**trkpt)
-            if "ele" in trkpt:
+            if trkpt.get("ele") is not None:
                 yield '    <ele>{ele}</ele>\n'.format(**trkpt)
             if "time" in trkpt:
                 yield '    <time>{time}</time>\n'.format(**trkpt)
diff --git a/tests/test_fitdump.py b/tests/test_fitdump.py
new file mode 100644
index 0000000..89439d0
--- /dev/null
+++ b/tests/test_fitdump.py
@@ -0,0 +1,40 @@
+import importlib.util
+import pathlib
+import unittest
+import xml.etree.ElementTree as ElementTree
+from importlib.machinery import SourceFileLoader
+
+
+FITDUMP_PATH = pathlib.Path(__file__).parents[1] / "scripts" / "fitdump"
+FITDUMP_SPEC = importlib.util.spec_from_loader("fitdump", SourceFileLoader("fitdump", str(FITDUMP_PATH)))
+fitdump = importlib.util.module_from_spec(FITDUMP_SPEC)
+FITDUMP_SPEC.loader.exec_module(fitdump)
+
+
+class Field:
+    def __init__(self, name, value):
+        self.name = name
+        self.value = value
+
+
+class Record(list):
+    name = "record"
+
+
+class GenerateGpxTestCase(unittest.TestCase):
+    def test_invalid_coordinates_and_elevation_are_omitted(self):
+        records = [
+            Record([Field("position_lat", None), Field("position_long", 1)]),
+            Record([Field("position_lat", 1), Field("position_long", 2), Field("enhanced_altitude", None)]),
+        ]
+
+        root = ElementTree.fromstring("".join(fitdump.generate_gpx(records)))
+        namespace = {"gpx": "http://www.topografix.com/GPX/1/1"}
+        points = root.findall(".//gpx:trkpt", namespace)
+
+        self.assertEqual(1, len(points))
+        self.assertIsNone(points[0].find("gpx:ele", namespace))
+
+
+if __name__ == "__main__":
+    unittest.main()