diff --git a/posthog/client.py b/posthog/client.py
index 59ccb9dc..eacaac28 100644
--- a/posthog/client.py
+++ b/posthog/client.py
@@ -2329,6 +2329,9 @@ def _enqueue(self, msg, disable_geoip, lane=None, property_allowlist=None):
                 k: v for k, v in msg["properties"].items() if k in property_allowlist
             }
 
+        if isinstance(msg.get("properties"), dict):
+            msg["properties"] = {k: v for k, v in msg["properties"].items() if v is not None}
+
         msg["distinct_id"] = stringify_id(msg.get("distinct_id", None))
 
         msg = clean(msg)
diff --git a/posthog/test/test_client.py b/posthog/test/test_client.py
index 087a79ca..65af41b2 100644
--- a/posthog/test/test_client.py
+++ b/posthog/test/test_client.py
@@ -402,6 +402,23 @@ def test_basic_capture(self):
             assert msg["properties"]["$os"] == mock.ANY
             assert msg["properties"]["$os_version"] == mock.ANY
 
+    def test_capture_sanitizes_none_properties(self):
+        with mock.patch("posthog.client.batch_post") as mock_post:
+            client = Client(FAKE_TEST_API_KEY, on_error=self.set_fail, sync_mode=True)
+            client.capture(
+                "python test event", 
+                distinct_id="distinct_id", 
+                properties={"valid": 123, "invalid": None}
+            )
+            self.assertFalse(self.failed)
+
+            mock_post.assert_called_once()
+            msg = mock_post.call_args[1]["batch"][0]
+            
+            self.assertIn("valid", msg["properties"])
+            self.assertEqual(msg["properties"]["valid"], 123)
+            self.assertNotIn("invalid", msg["properties"])
+
     def test_capture_omits_is_server_when_disabled(self):
         with mock.patch("posthog.client.batch_post") as mock_post:
             client = Client(