diff --git a/ops/jujuversion.py b/ops/jujuversion.py
index 57153e332..ec701c660 100755
--- a/ops/jujuversion.py
+++ b/ops/jujuversion.py
@@ -71,7 +71,7 @@ def __eq__(self, other: Union[str, 'JujuVersion']) -> bool:
             and self.build == other.build
             and self.patch == other.patch)
 
-    def __lt__(self, other: 'JujuVersion') -> bool:
+    def __lt__(self, other: Union[str, 'JujuVersion']) -> bool:
         if self is other:
             return False
         if isinstance(other, str):
diff --git a/pyproject.toml b/pyproject.toml
index c7c210455..f8089debc 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -29,8 +29,9 @@ docstring-convention = "google"
 
 [tool.pyright]
 include = ["ops/*.py", "ops/_private/*.py",
-    "test/test_log.py",
     "test/test_infra.py",
+    "test/test_jujuversion.py",
+    "test/test_log.py",
 ]
 pythonVersion = "3.8" # check no python > 3.8 features are used
 pythonPlatform = "All"
diff --git a/test/test_jujuversion.py b/test/test_jujuversion.py
index a22cb050d..25692622e 100755
--- a/test/test_jujuversion.py
+++ b/test/test_jujuversion.py
@@ -41,7 +41,7 @@ def test_parsing(self):
             self.assertEqual(v.patch, patch)
             self.assertEqual(v.build, build)
 
-    @unittest.mock.patch('os.environ', new={})
+    @unittest.mock.patch('os.environ', new={})  # type: ignore
     def test_from_environ(self):
         # JUJU_VERSION is not set
         v = ops.JujuVersion.from_environ()