diff --git a/leo_fw/leo_fw/board.py b/leo_fw/leo_fw/board.py
index 84f6b8d..f8cf2c4 100644
--- a/leo_fw/leo_fw/board.py
+++ b/leo_fw/leo_fw/board.py
@@ -50,7 +50,8 @@ def determine_board(node: rclpy.Node) -> Optional[BoardType]:
         future = get_board_type.call_async(Trigger.Request())
         rclpy.spin_until_future_complete(node, future, timeout_sec=5.0)
         if future.done() and not future.exception():
-            result = future.result()
+            result: Trigger.Response | None = future.result()
+            assert result is not None
             type_str = result.message
             if type_str == str(BoardType.CORE2):
                 board_type = BoardType.CORE2
@@ -76,7 +77,8 @@ def check_firmware_version(node: rclpy.Node) -> str:
         future = get_firmware_version.call_async(Trigger.Request())
         rclpy.spin_until_future_complete(node, future, timeout_sec=5.0)
         if future.done() and not future.exception():
-            result = future.result()
+            result: Trigger.Response | None = future.result()
+            assert result is not None
             firmware_version = result.message
         get_firmware_version.destroy()
 
diff --git a/leo_fw/leo_fw/nodes/parameter_bridge.py b/leo_fw/leo_fw/nodes/parameter_bridge.py
index 7e4afd3..61d5c45 100644
--- a/leo_fw/leo_fw/nodes/parameter_bridge.py
+++ b/leo_fw/leo_fw/nodes/parameter_bridge.py
@@ -206,12 +206,16 @@ def send_params(self) -> tuple[bool, int]:
         param_request.parameters = self.parse_firmware_parameters()
         future = self.firmware_parameter_service_client.call_async(param_request)
 
+        assert self.executor is not None
         self.executor.spin_until_future_complete(future, 5.0)
 
-        if future.result():
+        set_params_response: SetParameters.Response | None = future.result()
+        if set_params_response is not None:
             result: SetParametersResult
             param: ParameterMsg
-            for result, param in zip(future.result().results, param_request.parameters):
+            for result, param in zip(
+                set_params_response.results, param_request.parameters
+            ):
                 if not result.successful:
                     self.get_logger().warning(
                         f"Parameter '{param.name}' not set. Reason: '{result.reason}'"
@@ -234,6 +238,7 @@ def trigger_boot(self) -> bool:
         boot_request = Trigger.Request()
         boot_future = self.frimware_boot_service_client.call_async(boot_request)
 
+        assert self.executor is not None
         self.executor.spin_until_future_complete(boot_future, 5.0)
 
         if boot_future.result():
diff --git a/leo_fw/leo_fw/utils.py b/leo_fw/leo_fw/utils.py
index 15b407c..7c0be9b 100644
--- a/leo_fw/leo_fw/utils.py
+++ b/leo_fw/leo_fw/utils.py
@@ -99,7 +99,7 @@ def query_yes_no(question: str, default: str = "yes") -> bool:
             return valid[default]
         if choice in valid:
             return valid[choice]
-        print("Please respond with 'yes' or 'no' " "(or 'y' or 'n').")
+        print("Please respond with 'yes' or 'no' (or 'y' or 'n').")
 
 
 def prompt_options(options: list[tuple[str, T]], default: int = 1) -> T: