diff --git a/src/py-opentimelineio/opentimelineio/adapters/fcp_xml.py b/src/py-opentimelineio/opentimelineio/adapters/fcp_xml.py
index 98e1fd11c..e32763c0a 100644
--- a/src/py-opentimelineio/opentimelineio/adapters/fcp_xml.py
+++ b/src/py-opentimelineio/opentimelineio/adapters/fcp_xml.py
@@ -1832,7 +1832,12 @@ def _build_marker(marker):
         marker_e, 'in',
         text=f'{marked_range.start_time.value:.0f}'
     )
-    _append_new_sub_element(marker_e, 'out', text='-1')
+    _append_new_sub_element(
+        marker_e, 'out',
+        text='{:.0f}'.format(
+            marked_range.start_time.value + marked_range.duration.value
+        )
+    )
 
     return marker_e
 
diff --git a/tests/test_fcp7_xml_adapter.py b/tests/test_fcp7_xml_adapter.py
index e5a949d3b..4139e3469 100644
--- a/tests/test_fcp7_xml_adapter.py
+++ b/tests/test_fcp7_xml_adapter.py
@@ -1256,6 +1256,17 @@ def test_roundtrip_mem2disk2mem(self):
             )
         )
 
+        timeline.tracks.markers.append(
+            schema.Marker(
+                name='test_timeline_marker_range',
+                marked_range=opentime.TimeRange(
+                    opentime.RationalTime(123, RATE),
+                    opentime.RationalTime(11, RATE),
+                ),
+                metadata={'fcp_xml': {'comment': 'my_comment'}}
+            )
+        )
+
         v1[1].markers.append(
             schema.Marker(
                 name='test_clip_marker',
@@ -1266,6 +1277,17 @@ def test_roundtrip_mem2disk2mem(self):
             )
         )
 
+        v1[1].markers.append(
+            schema.Marker(
+                name='test_clip_marker_range',
+                marked_range=opentime.TimeRange(
+                    opentime.RationalTime(125, RATE),
+                    opentime.RationalTime(6, RATE)
+                ),
+                metadata={'fcp_xml': {'comment': 'my_comment'}}
+            )
+        )
+
         # make sure that global_start_time.rate survives the round trip
         timeline.global_start_time = opentime.RationalTime(100, RATE)