diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index bbb4eb1..81c7923 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -3,7 +3,7 @@ exclude: ^(.secrets|docs)/
 
 repos:
   - repo: https://github.com/astral-sh/ruff-pre-commit
-    rev: v0.8.4
+    rev: v0.9.1
     hooks:
       - id: ruff         # linter
       - id: ruff-format  # formatter
diff --git a/requirements_dev.txt b/requirements_dev.txt
index 55bb5fc..f47afd7 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -10,7 +10,7 @@
 
 # used for development (linting)
   pre-commit >= 4.0.1
-  ruff >= 0.8.4                                  # also: pre-commit-config.yaml
+  ruff >= 0.9.1                                  # also: pre-commit-config.yaml
 
 # used for development (typing)
   mypy >= 1.13.0
diff --git a/src/evohomeasync/entities.py b/src/evohomeasync/entities.py
index e82b90d..704c597 100644
--- a/src/evohomeasync/entities.py
+++ b/src/evohomeasync/entities.py
@@ -206,7 +206,7 @@ def name(self) -> str:
 
     @property  # appears to be the zone idx (not in evohomeclientv2)
     def idx(self) -> str:
-        return f"{self._config["instance"]:02X}"
+        return f"{self._config['instance']:02X}"
 
     @property
     def max_heat_setpoint(self) -> float:
diff --git a/src/evohomeasync/main.py b/src/evohomeasync/main.py
index 7a12ff4..a050ab3 100644
--- a/src/evohomeasync/main.py
+++ b/src/evohomeasync/main.py
@@ -124,7 +124,7 @@ async def _get_config(self) -> list[EvoTcsInfoDictT]:
         assert self._user_info is not None  # mypy (internal hint)
 
         if self._user_locs is None:
-            url = f"locations?userId={self._user_info["user_id"]}&allData=True"
+            url = f"locations?userId={self._user_info['user_id']}&allData=True"
             self._user_locs = await self.auth.get(url, schema=SCH_GET_ACCOUNT_LOCS)  # type: ignore[assignment]
 
         assert self._user_locs is not None  # mypy (internal hint)
diff --git a/src/evohomeasync2/control_system.py b/src/evohomeasync2/control_system.py
index 1dab209..ccd327e 100644
--- a/src/evohomeasync2/control_system.py
+++ b/src/evohomeasync2/control_system.py
@@ -319,7 +319,7 @@ async def restore_by_id(sched: EvoScheduleDhwT | EvoScheduleZoneT) -> bool:
 
             else:
                 self._logger.warning(
-                    f"Ignoring schedule of {id_} ({sched.get("name")}): unknown id"
+                    f"Ignoring schedule of {id_} ({sched.get('name')}): unknown id"
                     ", consider matching by name rather than by id"
                 )
                 return False
diff --git a/tests/tests/conftest.py b/tests/tests/conftest.py
index 9fbf309..5dac173 100644
--- a/tests/tests/conftest.py
+++ b/tests/tests/conftest.py
@@ -149,7 +149,7 @@ def location_status_fixture(folder: Path, loc_id: str) -> JsonObjectType:
 def zone_schedule_fixture(folder: Path, zon_type: str) -> JsonObjectType:
     """Load the JSON of the schedule of a dhw/zone."""
     return _load_fixture(
-        folder, f"schedule_{"dhw" if zon_type == "domesticHotWater" else "zone"}.json"
+        folder, f"schedule_{'dhw' if zon_type == 'domesticHotWater' else 'zone'}.json"
     )  # type: ignore[return-value]
 
 
diff --git a/tests/tests_rf/test_v2_urls_auth.py b/tests/tests_rf/test_v2_urls_auth.py
index 1b29d0a..d6d7e9a 100644
--- a/tests/tests_rf/test_v2_urls_auth.py
+++ b/tests/tests_rf/test_v2_urls_auth.py
@@ -78,7 +78,7 @@ async def _test_user_locations(evo: EvohomeClientv2) -> None:
     )  # type: ignore[assignment]
 
     #
-    url = f"location/installationInfo?userId={user_info["userId"]}"
+    url = f"location/installationInfo?userId={user_info['userId']}"
     _ = await should_work_v2(
         evo.auth,
         HTTPMethod.GET,