diff --git a/project.py b/project.py
index c91ae217..93d9dcba 100644
--- a/project.py
+++ b/project.py
@@ -3982,7 +3982,7 @@ class ManifestProject(MetaProject):
     @property
     def depth(self):
         """Partial clone depth."""
-        return self.config.GetString("repo.depth")
+        return self.config.GetInt("repo.depth")
 
     @property
     def clone_filter(self):
diff --git a/tests/test_project.py b/tests/test_project.py
index 42f0f6e5..83cfe0a4 100644
--- a/tests/test_project.py
+++ b/tests/test_project.py
@@ -507,7 +507,10 @@ class ManifestPropertiesFetchedCorrectly(unittest.TestCase):
             self.assertFalse(fakeproj.partial_clone)
 
             fakeproj.config.SetString("repo.depth", "48")
-            self.assertEqual(fakeproj.depth, "48")
+            self.assertEqual(fakeproj.depth, 48)
+
+            fakeproj.config.SetString("repo.depth", "invalid_depth")
+            self.assertEqual(fakeproj.depth, None)
 
             fakeproj.config.SetString("repo.clonefilter", "blob:limit=10M")
             self.assertEqual(fakeproj.clone_filter, "blob:limit=10M")