diff --git a/NightLight.Core.Tests/InteractionListGenerators.fs b/NightLight.Core.Tests/InteractionListGenerators.fs
index 8202a63..c4412a6 100644
--- a/NightLight.Core.Tests/InteractionListGenerators.fs
+++ b/NightLight.Core.Tests/InteractionListGenerators.fs
@@ -70,15 +70,7 @@ let ensureLightHasPower (light: Light) (genInteractions: Gen<Interaction list>)
 let ensurePartOfDayIs (desiredPartOfDay: PartOfDay) (genInteractions: Gen<Interaction list>) =
     genInteractions
     |> Gen.bind (fun interactions ->
-        let maybeActualTime =
-            interactions
-            |> Seq.choose (fun interaction ->
-                match interaction with
-                | Interaction.TimeChanged time -> Some time
-                | _ -> None)
-            |> Seq.tryLast
-
-        if maybeActualTime |> Option.map getPartOfDay = Some desiredPartOfDay then
+        if getPartOfDayAfterInteractions interactions = desiredPartOfDay then
             Gen.constant interactions
         else
             desiredPartOfDay
diff --git a/NightLight.Core.Tests/NightLightTests.fs b/NightLight.Core.Tests/NightLightTests.fs
index c55ec08..8ed5ab3 100644
--- a/NightLight.Core.Tests/NightLightTests.fs
+++ b/NightLight.Core.Tests/NightLightTests.fs
@@ -85,10 +85,11 @@ type NightLightTests() =
         (light: Light)
         =
         concatGens
-            [ genBiasedInteractions light |> ensurePartOfDayIs Night
+            [ genBiasedInteractions light
+              |> ensureStartsWithTimeChanged
+              |> ensurePartOfDayIs Night
               genTimeChangedToPartOfDay Day |> Gen.map List.singleton
               genBiasedInteractionsExcept light _.IsRemoteInteraction ]
-        |> ensureStartsWithTimeChanged
         |> ensureLightHasPower light
         |> Arb.fromGen
         |> Prop.forAll