diff --git a/changelog.d/14869.bugfix b/changelog.d/14869.bugfix
new file mode 100644
index 0000000000..865b597741
--- /dev/null
+++ b/changelog.d/14869.bugfix
@@ -0,0 +1 @@
+Fix a bug introduced in v1.75.0rc1 that caused experimental support for deleting account data to raise an internal server error while using an account data writer worker.
\ No newline at end of file
diff --git a/synapse/handlers/account_data.py b/synapse/handlers/account_data.py
index 797de46dbc..7e01c18c6c 100644
--- a/synapse/handlers/account_data.py
+++ b/synapse/handlers/account_data.py
@@ -155,9 +155,6 @@ class AccountDataHandler:
             max_stream_id = await self._store.remove_account_data_for_room(
                 user_id, room_id, account_data_type
             )
-            if max_stream_id is None:
-                # The referenced account data did not exist, so no delete occurred.
-                return None
 
             self._notifier.on_new_event(
                 StreamKeyType.ACCOUNT_DATA, max_stream_id, users=[user_id]
@@ -230,9 +227,6 @@ class AccountDataHandler:
             max_stream_id = await self._store.remove_account_data_for_user(
                 user_id, account_data_type
             )
-            if max_stream_id is None:
-                # The referenced account data did not exist, so no delete occurred.
-                return None
 
             self._notifier.on_new_event(
                 StreamKeyType.ACCOUNT_DATA, max_stream_id, users=[user_id]
@@ -248,7 +242,6 @@ class AccountDataHandler:
                 instance_name=random.choice(self._account_data_writers),
                 user_id=user_id,
                 account_data_type=account_data_type,
-                content={},
             )
             return response["max_stream_id"]
 
diff --git a/synapse/storage/databases/main/account_data.py b/synapse/storage/databases/main/account_data.py
index 2d2ba74347..a9843f6e17 100644
--- a/synapse/storage/databases/main/account_data.py
+++ b/synapse/storage/databases/main/account_data.py
@@ -581,7 +581,7 @@ class AccountDataWorkerStore(PushRulesWorkerStore, CacheInvalidationWorkerStore)
 
     async def remove_account_data_for_room(
         self, user_id: str, room_id: str, account_data_type: str
-    ) -> Optional[int]:
+    ) -> int:
         """Delete the room account data for the user of a given type.
 
         Args:
@@ -632,15 +632,13 @@ class AccountDataWorkerStore(PushRulesWorkerStore, CacheInvalidationWorkerStore)
                 next_id,
             )
 
-            if not row_updated:
-                return None
-
-            self._account_data_stream_cache.entity_has_changed(user_id, next_id)
-            self.get_room_account_data_for_user.invalidate((user_id,))
-            self.get_account_data_for_room.invalidate((user_id, room_id))
-            self.get_account_data_for_room_and_type.prefill(
-                (user_id, room_id, account_data_type), {}
-            )
+            if row_updated:
+                self._account_data_stream_cache.entity_has_changed(user_id, next_id)
+                self.get_room_account_data_for_user.invalidate((user_id,))
+                self.get_account_data_for_room.invalidate((user_id, room_id))
+                self.get_account_data_for_room_and_type.prefill(
+                    (user_id, room_id, account_data_type), {}
+                )
 
         return self._account_data_id_gen.get_current_token()
 
@@ -747,7 +745,7 @@ class AccountDataWorkerStore(PushRulesWorkerStore, CacheInvalidationWorkerStore)
         self,
         user_id: str,
         account_data_type: str,
-    ) -> Optional[int]:
+    ) -> int:
         """
         Delete a single piece of user account data by type.
 
@@ -833,14 +831,12 @@ class AccountDataWorkerStore(PushRulesWorkerStore, CacheInvalidationWorkerStore)
                 next_id,
             )
 
-            if not row_updated:
-                return None
-
-            self._account_data_stream_cache.entity_has_changed(user_id, next_id)
-            self.get_global_account_data_for_user.invalidate((user_id,))
-            self.get_global_account_data_by_type_for_user.prefill(
-                (user_id, account_data_type), {}
-            )
+            if row_updated:
+                self._account_data_stream_cache.entity_has_changed(user_id, next_id)
+                self.get_global_account_data_for_user.invalidate((user_id,))
+                self.get_global_account_data_by_type_for_user.prefill(
+                    (user_id, account_data_type), {}
+                )
 
         return self._account_data_id_gen.get_current_token()