diff --git a/spalloc_client/job.py b/spalloc_client/job.py
index 8d3df752c..9ef4b1e55 100644
--- a/spalloc_client/job.py
+++ b/spalloc_client/job.py
@@ -246,12 +246,12 @@ def __init__(self, *args: int, **kwargs: Union[float, str, None]):
         config = SpallocConfig(config_filenames)
 
         # Get protocol client options
-        hostname = kwargs.get("hostname", config.hostname)
+        hostname = cast(str, kwargs.get("hostname", config.hostname))
         owner = kwargs.get("owner", config.owner)
-        port = kwargs.get("port", config.port)
+        port = cast(int, kwargs.get("port", config.port))
         self._reconnect_delay = kwargs.get("reconnect_delay",
                                            config.reconnect_delay)
-        self._timeout = kwargs.get("timeout", config.timeout)
+        self._timeout = cast(float, kwargs.get("timeout", config.timeout))
         if hostname is None:
             raise ValueError("A hostname must be specified.")
 
@@ -677,7 +677,7 @@ def _do_reconnect(self, finish_time: Optional[float]) -> None:
         time.sleep(max(0.0, delay))
         self._reconnect()
 
-    def wait_until_ready(self, timeout: Optional[int] = None) -> None:
+    def wait_until_ready(self, timeout: Optional[float] = None) -> None:
         """ Block until the job is allocated and ready.
 
         Parameters
diff --git a/spalloc_client/protocol_client.py b/spalloc_client/protocol_client.py
index 00ce2ffff..5eaa375e6 100644
--- a/spalloc_client/protocol_client.py
+++ b/spalloc_client/protocol_client.py
@@ -19,7 +19,7 @@
 import json
 import socket
 from types import TracebackType
-from typing import cast, Dict, Literal, Optional, Type, Union
+from typing import Any, cast, Dict, List, Literal, Optional, Type, Union
 from threading import current_thread, RLock, local, Thread
 
 from typing_extensions import Self
@@ -281,7 +281,7 @@ def _send_json(
 
     def call(self, name: str, timeout: Optional[float],
              *args: Union[int, str, None],
-             **kwargs: JsonValue) -> JsonValue:
+             **kwargs: Any) -> JsonValue:
         """ Send a command to the server and return the reply.
 
         Parameters
@@ -376,11 +376,12 @@ def wait_for_notification(
     # The bindings of the Spalloc protocol methods themselves; simplifies use
     # from IDEs.
 
-    def version(self, timeout: Optional[int] = None) -> str:
+    def version(self, timeout: Optional[float] = None) -> str:
         """ Ask what version of spalloc is running. """
         return cast(str, self.call("version", timeout))
 
-    def create_job(self, *args: int, **kwargs: str) -> int:
+    def create_job(self, *args: int,
+                   **kwargs: Union[float, str, List[str], None]) -> int:
         """
         Start a new job
         """
@@ -400,55 +401,55 @@ def job_keepalive(self, job_id: int,
         return cast(dict, self.call("job_keepalive", timeout, job_id))
 
     def get_job_state(self, job_id: int,
-                      timeout: Optional[int] = None) -> JsonObject:
+                      timeout: Optional[float] = None) -> JsonObject:
         """Get the state for this job """
         return cast(dict, self.call("get_job_state", timeout, job_id))
 
     def get_job_machine_info(self, job_id: int,
-                             timeout: Optional[int] = None) -> JsonObject:
+                             timeout: Optional[float] = None) -> JsonObject:
         """ Get info for this job. """
         return cast(dict, self.call("get_job_machine_info", timeout, job_id))
 
     def power_on_job_boards(self, job_id: int,
-                            timeout: Optional[int] = None) -> JsonObject:
+                            timeout: Optional[float] = None) -> JsonObject:
         """ Turn on the power on the jobs boards. """
         return cast(dict, self.call("power_on_job_boards", timeout, job_id))
 
     def power_off_job_boards(self, job_id: int,
-                             timeout: Optional[int] = None) -> JsonObject:
+                             timeout: Optional[float] = None) -> JsonObject:
         """ Turn off the power on the jobs boards. """
         return cast(dict, self.call("power_off_job_boards", timeout, job_id))
 
     def destroy_job(self, job_id: int, reason: Optional[str] = None,
-                    timeout: Optional[int] = None) -> JsonObject:
+                    timeout: Optional[float] = None) -> JsonObject:
         """ Destroy the job """
         return cast(dict, self.call("destroy_job", timeout,
                                     job_id, reason=reason))
 
     def notify_job(self, job_id: Optional[int] = None,
-                   timeout: Optional[int] = None) -> JsonObject:
+                   timeout: Optional[float] = None) -> JsonObject:
         """ Turn on notification of job status changes. """
         return cast(dict, self.call("notify_job", timeout, job_id))
 
     def no_notify_job(self, job_id: Optional[int] = None,
-                      timeout: Optional[int] = None) -> JsonObject:
+                      timeout: Optional[float] = None) -> JsonObject:
         """ Turn off notification of job status changes. """
         return cast(dict, self.call("no_notify_job", timeout,
                                     job_id))
 
     def notify_machine(self, machine_name: Optional[str] = None,
-                       timeout: Optional[int] = None) -> JsonObject:
+                       timeout: Optional[float] = None) -> JsonObject:
         """ Turn on notification of machine status changes. """
         return cast(dict, self.call("notify_machine", timeout,
                                     machine_name))
 
     def no_notify_machine(self, machine_name: Optional[str] = None,
-                          timeout: Optional[int] = None) -> JsonObject:
+                          timeout: Optional[float] = None) -> JsonObject:
         """ Turn off notification of machine status changes. """
         return cast(dict, self.call("no_notify_machine", timeout,
                                     machine_name))
 
-    def list_jobs(self, timeout: Optional[int] = None) -> JsonObjectArray:
+    def list_jobs(self, timeout: Optional[float] = None) -> JsonObjectArray:
         """ Obtains a list of jobs currently running. """
         return cast(list, self.call("list_jobs", timeout))
 
@@ -459,14 +460,14 @@ def list_machines(self,
 
     def get_board_position(
             self, machine_name: str, x: int, y: int, z: int,
-            timeout: Optional[int] = None) -> JsonObject:  # pragma: no cover
+            timeout: Optional[float] = None) -> JsonObject:  # pragma: no cover
         """ Gets the position of board x, y, z on the given machine. """
         # pylint: disable=too-many-arguments
         return cast(dict, self.call("get_board_position", timeout,
                                     machine_name, x, y, z))
 
     def get_board_at_position(self, machine_name: str, x: int, y: int, z: int,
-                              timeout: Optional[int] = None
+                              timeout: Optional[float] = None
                               ) -> JsonObject:  # pragma: no cover
         """ Gets the board x, y, z on the requested machine. """
         # pylint: disable=too-many-arguments
@@ -480,7 +481,7 @@ def get_board_at_position(self, machine_name: str, x: int, y: int, z: int,
         frozenset("job_id chip_x chip_y".split())])
 
     def where_is(self, job_id: int, chip_x: int, chip_y: int,
-                 timeout: Optional[int] = None) -> JsonObject:
+                 timeout: Optional[float] = None) -> JsonObject:
         """ Reports where ion the Machine a job is running """
         # Test for whether sane arguments are passed.
         return cast(dict, self.call("where_is", timeout, job_id=job_id,
diff --git a/spalloc_client/scripts/job.py b/spalloc_client/scripts/job.py
index 0388fb947..ec80177c6 100644
--- a/spalloc_client/scripts/job.py
+++ b/spalloc_client/scripts/job.py
@@ -94,7 +94,7 @@ def _state_name(mapping: JsonObject) -> str:
     return state.name  # pylint: disable=no-member
 
 
-def show_job_info(t: Terminal, client: ProtocolClient, timeout: Optional[int],
+def show_job_info(t: Terminal, client: ProtocolClient, timeout: Optional[float],
                   job_id: int) -> None:
     """ Print a human-readable overview of a Job's attributes.
 
@@ -173,7 +173,7 @@ def show_job_info(t: Terminal, client: ProtocolClient, timeout: Optional[int],
     print(render_definitions(info))
 
 
-def watch_job(t: Terminal, client: ProtocolClient, timeout: Optional[int],
+def watch_job(t: Terminal, client: ProtocolClient, timeout: Optional[float],
               job_id: int) -> int:
     """ Re-print a job's information whenever the job changes.
 
@@ -207,7 +207,7 @@ def watch_job(t: Terminal, client: ProtocolClient, timeout: Optional[int],
             print("")
 
 
-def power_job(client: ProtocolClient, timeout: Optional[int],
+def power_job(client: ProtocolClient, timeout: Optional[float],
               job_id: int, power: bool) -> None:
     """ Power a job's boards on/off and wait for the action to complete.
 
@@ -256,7 +256,7 @@ def power_job(client: ProtocolClient, timeout: Optional[int],
                     f"job {job_id} in state {_state_name(state)}"))
 
 
-def list_ips(client: ProtocolClient, timeout: Optional[int],
+def list_ips(client: ProtocolClient, timeout: Optional[float],
              job_id: int) -> None:
     """ Print a CSV of board hostnames for all boards allocated to a job.
 
@@ -289,7 +289,7 @@ def list_ips(client: ProtocolClient, timeout: Optional[int],
         print(f"{x},{y},{hostname}")
 
 
-def destroy_job(client: ProtocolClient, timeout: Optional[int],
+def destroy_job(client: ProtocolClient, timeout: Optional[float],
                 job_id: int, reason: Optional[str] = None) -> None:
     """ Destroy a running job.
 
diff --git a/spalloc_client/scripts/support.py b/spalloc_client/scripts/support.py
index be4f51753..49e3a2a56 100644
--- a/spalloc_client/scripts/support.py
+++ b/spalloc_client/scripts/support.py
@@ -41,7 +41,7 @@ def exit(self) -> None:
         sys.exit(self._code)
 
 
-def version_verify(client: ProtocolClient, timeout: Optional[int]) -> None:
+def version_verify(client: ProtocolClient, timeout: Optional[float]) -> None:
     """
     Verify that the current version of the client is compatible
     """