diff --git a/backend/app/services/github/client.py b/backend/app/services/github/client.py
index babfd9d3..837ddbff 100644
--- a/backend/app/services/github/client.py
+++ b/backend/app/services/github/client.py
@@ -83,13 +83,14 @@ async def get_pull_request_head_sha(pr: ParsedPullRequest) -> str:
     head = data.get("head")
     if not isinstance(head, dict) or not isinstance(head.get("sha"), str):
         raise GitHubClientError("GitHub PR response missing head.sha")
-    return head["sha"]
+    # mypy: dict indexing returns Any; we've validated it's a str above.
+    return str(head["sha"])
 
 
 async def _find_check_run_id(*, owner: str, repo: str, ref: str, check_name: str) -> int | None:
     # Docs: GET /repos/{owner}/{repo}/commits/{ref}/check-runs
     url = f"{GITHUB_API_BASE_URL}/repos/{owner}/{repo}/commits/{ref}/check-runs"
-    params = {"check_name": check_name, "per_page": 100}
+    params: dict[str, str | int] = {"check_name": check_name, "per_page": 100}
     async with httpx.AsyncClient(timeout=10) as client:
         resp = await client.get(url, headers=_auth_headers(), params=params)
     if resp.status_code >= 400:
diff --git a/backend/app/services/github/mission_control_approval_check.py b/backend/app/services/github/mission_control_approval_check.py
index 0de8ca89..eb446f6a 100644
--- a/backend/app/services/github/mission_control_approval_check.py
+++ b/backend/app/services/github/mission_control_approval_check.py
@@ -21,7 +21,7 @@ A periodic reconciliation job should call the sync functions as a safety net.
 from __future__ import annotations
 
 from dataclasses import dataclass
-from typing import Literal
+from typing import Literal, cast
 from uuid import UUID
 
 from sqlmodel import col, select
@@ -360,7 +360,8 @@ async def reconcile_github_approval_checks_for_board(
         .where(col(TaskCustomFieldDefinition.organization_id) == org_id)
         .where(col(TaskCustomFieldDefinition.field_key) == "github_pr_url")
     )
-    rows = list(await session.exec(stmt))
+    raw_rows = list(await session.exec(stmt))
+    rows = cast(list[tuple[object]], raw_rows)
 
     pr_urls: set[str] = set()
     for (value,) in rows:
@@ -383,11 +384,12 @@ async def reconcile_mission_control_approval_checks_for_all_boards() -> int:
     """
 
     async with async_session_maker() as session:
-        board_ids = list(
+        raw_board_ids = list(
             await session.exec(
                 select(col(Board.id)).order_by(col(Board.created_at).asc()),
             ),
         )
+        board_ids = cast(list[UUID], raw_board_ids)
         processed = 0
         for board_id in board_ids:
             try: