diff --git a/wheel/chia_rs.pyi b/wheel/chia_rs.pyi
index 13ebda3c3..fdc3e3406 100644
--- a/wheel/chia_rs.pyi
+++ b/wheel/chia_rs.pyi
@@ -812,7 +812,7 @@ class HeaderBlock:
     total_iters: int
     log_string: str
     is_transaction_block: bool
-    first_in_sub_slots: bool
+    first_in_sub_slot: bool
     def __init__(
         self,
         finished_sub_slots: Sequence[EndOfSubSlotBundle],
diff --git a/wheel/generate_type_stubs.py b/wheel/generate_type_stubs.py
index d1f459f5f..81c22ccab 100644
--- a/wheel/generate_type_stubs.py
+++ b/wheel/generate_type_stubs.py
@@ -175,7 +175,7 @@ def parse_rust_source(filename: str) -> List[Tuple[str, List[str]]]:
         "total_iters: int",
         "log_string: str",
         "is_transaction_block: bool",
-        "first_in_sub_slots: bool",
+        "first_in_sub_slot: bool",
     ],
     "RewardChainBlock": [
         "def get_unfinished(self) -> RewardChainBlockUnfinished: ...",