diff --git a/src/questdb/ingress.pyi b/src/questdb/ingress.pyi
index 7989a79a..0595c24c 100644
--- a/src/questdb/ingress.pyi
+++ b/src/questdb/ingress.pyi
@@ -1033,7 +1033,7 @@ class Sender:
         *,
         symbols: Optional[Dict[str, str]] = None,
         columns: Optional[
-            Dict[str, Union[bool, int, float, str, TimestampMicros, datetime, np.ndarray]]
+            Dict[str, Union[None, bool, int, float, str, TimestampMicros, datetime, np.ndarray]]
         ] = None,
         at: Union[TimestampNanos, datetime, ServerTimestampType],
     ) -> Sender:
diff --git a/src/questdb/ingress.pyx b/src/questdb/ingress.pyx
index b763f909..ac7bcb65 100644
--- a/src/questdb/ingress.pyx
+++ b/src/questdb/ingress.pyx
@@ -2533,7 +2533,7 @@ cdef class Sender:
             symbols: Optional[Dict[str, str]]=None,
             columns: Optional[Dict[
                 str,
-                Union[bool, int, float, str, TimestampMicros, datetime.datetime, numpy.ndarray]]]=None,
+                Union[None, bool, int, float, str, TimestampMicros, datetime.datetime, numpy.ndarray]]]=None,
             at: Union[TimestampNanos, datetime.datetime, ServerTimestampType]):
         """
         Write a row to the internal buffer.