diff --git a/NightLight.Core.Tests/FakeHome.fs b/NightLight.Core.Tests/FakeHome.fs
index df2da1b..f9b9d2d 100644
--- a/NightLight.Core.Tests/FakeHome.fs
+++ b/NightLight.Core.Tests/FakeHome.fs
@@ -59,23 +59,20 @@ type FakeHome(now: DateTime) =
 
     member _.LightStates = friendlyNameToFakeLight.Values |> Seq.map _.LightWithState
 
-    member _.Interact(interaction: Interaction) : Result<unit, ParseEventError> =
-        result {
-            match interaction with
-            | HumanInteraction(LightTurnedOn light) ->
-                friendlyNameToFakeLight[light.FriendlyName].TurnOn()
+    member _.Interact(interaction: Interaction) =
+        match interaction with
+        | HumanInteraction(LightTurnedOn light) ->
+            friendlyNameToFakeLight[light.FriendlyName].TurnOn()
 
-                do!
-                    { Topic = "zigbee2mqtt/bridge/event"
-                      Payload =
-                        $@"{{
-                            ""type"": ""device_announce"",
-                            ""data"": {{ ""friendly_name"": ""{light.FriendlyName}"" }}
-                          }}" }
-                    |> nightLightStateMachine.SendMessage
-            | HumanInteraction(LightTurnedOff light) -> friendlyNameToFakeLight[light.FriendlyName].TurnOff()
-            | TimeChanged time -> do! nightLightStateMachine.ChangeTime time
+            { Topic = "zigbee2mqtt/bridge/event"
+              Payload =
+                $@"{{
+                    ""type"": ""device_announce"",
+                    ""data"": {{ ""friendly_name"": ""{light.FriendlyName}"" }}
+                  }}" }
+            |> nightLightStateMachine.SendMessage
+        | HumanInteraction(LightTurnedOff light) -> friendlyNameToFakeLight[light.FriendlyName].TurnOff()
+        | TimeChanged time -> nightLightStateMachine.ChangeTime time
 
-            nightLightStateMachine.TransmittedCommands |> Seq.iter processCommand
-            nightLightStateMachine.ClearTransmittedCommands()
-        }
+        nightLightStateMachine.TransmittedCommands |> Seq.iter processCommand
+        nightLightStateMachine.ClearTransmittedCommands()
diff --git a/NightLight.Core.Tests/NightLightStateMachine.fs b/NightLight.Core.Tests/NightLightStateMachine.fs
index 0379a3b..f552cb1 100644
--- a/NightLight.Core.Tests/NightLightStateMachine.fs
+++ b/NightLight.Core.Tests/NightLightStateMachine.fs
@@ -11,12 +11,18 @@ type NightLightStateMachine(now: DateTime) =
 
     let transmittedCommands = new List<Message>()
 
+    let assertIsOk (result: Result<unit, 'a>) : unit =
+        match result with
+        | Ok() -> ()
+        | Error error -> failwith $"Expected Ok, got Error {error}"
+
     let sendEvent event =
         result {
             let! newState, commands = onEventReceived state event
             state <- newState
             transmittedCommands.AddRange commands
         }
+        |> assertIsOk
 
     member _.TransmittedCommands = transmittedCommands.AsReadOnly()
 
diff --git a/NightLight.Core.Tests/NightLightTests.fs b/NightLight.Core.Tests/NightLightTests.fs
index b7419fd..0fe7190 100644
--- a/NightLight.Core.Tests/NightLightTests.fs
+++ b/NightLight.Core.Tests/NightLightTests.fs
@@ -2,15 +2,9 @@ module NightLight.Core.Tests.NightLightTests
 
 open FsCheck.Xunit
 
-let private assertIsOk (result: Result<unit, 'a>) : unit =
-    match result with
-    | Ok() -> ()
-    | Error error -> failwith $"Expected Ok, got Error {error}"
-
 [<Property(Arbitrary = [| typeof<Arbitraries> |])>]
 let ``Brightness should always be under 255`` (fakeHome: FakeHome) (interactions: Interaction list) =
-    interactions
-    |> Seq.iter (fun interaction -> fakeHome.Interact interaction |> assertIsOk)
+    interactions |> Seq.iter (fun interaction -> fakeHome.Interact interaction)
 
     fakeHome.LightStates
     |> Seq.choose (fun (_, state) ->