diff --git a/skydriver/database/interface.py b/skydriver/database/interface.py
index 655d0063..f7f6716c 100644
--- a/skydriver/database/interface.py
+++ b/skydriver/database/interface.py
@@ -61,7 +61,7 @@ async def post(
         scanner_server_args: str,
         tms_args_list: list[str],
         env_vars: schema.EnvVars,
-        classifiers: dict[str, str | bool | float | int],
+        classifiers: dict[str, str | bool | float | int | None],
         priority: int,
     ) -> schema.Manifest:
         """Create `schema.Manifest` doc."""
diff --git a/skydriver/database/schema.py b/skydriver/database/schema.py
index 985b18fe..8f88694c 100644
--- a/skydriver/database/schema.py
+++ b/skydriver/database/schema.py
@@ -255,7 +255,7 @@ class Manifest(ScanIDDataclass):
     )
 
     # open to requestor
-    classifiers: dict[str, str | bool | float | int] = dc.field(default_factory=dict)
+    classifiers: dict[str, str | bool | float | int | None] = dc.field(default_factory=dict)
 
     # i3 event -- grabbed by scanner central server
     i3_event_id: str = ""  # id to i3_event coll
diff --git a/skydriver/rest_handlers.py b/skydriver/rest_handlers.py
index ef217408..b803bac8 100644
--- a/skydriver/rest_handlers.py
+++ b/skydriver/rest_handlers.py
@@ -297,12 +297,12 @@ def _validate_request_clusters(
     return list_tups
 
 
-def _classifiers_validator(val: Any) -> dict[str, str | bool | float | int]:
+def _classifiers_validator(val: Any) -> dict[str, str | bool | float | int | None]:
     # type checks
     if not isinstance(val, dict):
         raise argparse.ArgumentTypeError("must be a dict")
-    if any(v for v in val.values() if not isinstance(v, str | bool | float | int)):
-        raise argparse.ArgumentTypeError("entry must be 'str | bool | float | int'")
+    if any(v for v in val.values() if not isinstance(v, str | bool | float | int | None)):
+        raise argparse.ArgumentTypeError("entry must be 'str | bool | float | int | None'")
 
     # size check
     if len(val) > MAX_CLASSIFIERS_LEN: