diff --git a/postgrest/base_request_builder.py b/postgrest/base_request_builder.py
index 07071d8c..9afb5341 100644
--- a/postgrest/base_request_builder.py
+++ b/postgrest/base_request_builder.py
@@ -330,6 +330,8 @@ def is_(self: Self, column: str, value: Any) -> Self:
             column: The name of the column to apply a filter on
             value: The value to filter by
         """
+        if value is None:
+            value = "null"
         return self.filter(column, Filters.IS, value)
 
     def like(self: Self, column: str, pattern: str) -> Self: