diff --git a/readthedocs/projects/tasks/utils.py b/readthedocs/projects/tasks/utils.py
index 8de3c4d8f4e..e318b34466d 100644
--- a/readthedocs/projects/tasks/utils.py
+++ b/readthedocs/projects/tasks/utils.py
@@ -126,6 +126,10 @@ def finish_unhealthy_builds():
     builds_finished = []
     builds = Build.objects.filter(query)[:50]
     for build in builds:
+        if build.commands.exists():
+            # Try to update the build length if there is at least one command
+            build.length = (timezone.now() - build.commands.first().start_time).seconds
+
         build.success = False
         build.state = BUILD_STATE_CANCELLED
         build.save()
diff --git a/readthedocs/rtd_tests/tests/test_projects_tasks.py b/readthedocs/rtd_tests/tests/test_projects_tasks.py
index a21b2030426..08d654a5b0e 100644
--- a/readthedocs/rtd_tests/tests/test_projects_tasks.py
+++ b/readthedocs/rtd_tests/tests/test_projects_tasks.py
@@ -13,7 +13,7 @@
     BUILD_STATE_TRIGGERED,
     EXTERNAL,
 )
-from readthedocs.builds.models import Build, Version
+from readthedocs.builds.models import Build, BuildCommandResult, Version
 from readthedocs.projects.models import Feature, Project
 from readthedocs.projects.tasks.utils import finish_unhealthy_builds, send_external_build_status
 
@@ -93,6 +93,8 @@ def test_finish_unhealthy_builds_task(self, mocked_app):
             healthcheck=timezone.now() - datetime.timedelta(minutes=15),
         )
 
+        get(BuildCommandResult, build=build_3, start_time=timezone.now())
+
         finish_unhealthy_builds()
 
         build_1.refresh_from_db()
@@ -103,5 +105,6 @@ def test_finish_unhealthy_builds_task(self, mocked_app):
 
         build_3.refresh_from_db()
         self.assertEqual(build_3.state, BUILD_STATE_CANCELLED)
+        self.assertIsNotNone(build_3.length)
         self.assertEqual(build_3.success, False)
         self.assertEqual(build_3.notifications.count(), 1)