diff --git a/internal/nomad/nomad.go b/internal/nomad/nomad.go
index 13be4dd..9515d37 100644
--- a/internal/nomad/nomad.go
+++ b/internal/nomad/nomad.go
@@ -390,10 +390,10 @@ func filterDuplicateEvents(alloc *nomadApi.Allocation, allocations storage.Stora
 		return true
 	case !ok:
 		// This case happens in case of an error or when an event that led to the deletion of the alloc data is duplicated.
-		log.WithField("alloc", alloc).Debug("Ignoring unknown allocation")
+		log.WithField("allocID", alloc.ID).Debug("Ignoring unknown allocation")
 		return false
 	case alloc.ClientStatus == allocData.allocClientStatus && alloc.DesiredStatus == allocData.allocDesiredStatus:
-		log.WithField("alloc", alloc).Debug("Ignoring duplicate event")
+		log.WithField("allocID", alloc.ID).Debug("Ignoring duplicate event")
 		return false
 	default:
 		return true
diff --git a/internal/nomad/nomad_test.go b/internal/nomad/nomad_test.go
index f95d78c..9b55751 100644
--- a/internal/nomad/nomad_test.go
+++ b/internal/nomad/nomad_test.go
@@ -12,7 +12,6 @@ import (
 	"github.com/openHPI/poseidon/pkg/nullio"
 	"github.com/openHPI/poseidon/pkg/storage"
 	"github.com/openHPI/poseidon/tests"
-	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/mock"
 	"github.com/stretchr/testify/suite"
 	"io"
@@ -241,6 +240,7 @@ func eventForEvaluation(t *testing.T, eval *nomadApi.Evaluation) nomadApi.Event
 // simulateNomadEventStream streams the given events sequentially to the stream channel.
 // It returns how many events have been processed until an error occurred.
 func simulateNomadEventStream(
+	ctx context.Context,
 	stream chan<- *nomadApi.Events,
 	errChan chan error,
 	events []*nomadApi.Events,
@@ -259,7 +259,7 @@ func simulateNomadEventStream(
 	// Wait for last event being processed
 	var err error
 	select {
-	case <-time.After(10 * time.Millisecond):
+	case <-ctx.Done():
 	case err = <-errChan:
 	}
 	return eventsProcessed, err
@@ -268,10 +268,10 @@ func simulateNomadEventStream(
 // runEvaluationMonitoring simulates events streamed from the Nomad event stream
 // to the MonitorEvaluation method. It starts the MonitorEvaluation function as a goroutine
 // and sequentially transfers the events from the given array to a channel simulating the stream.
-func runEvaluationMonitoring(events []*nomadApi.Events) (eventsProcessed int, err error) {
+func runEvaluationMonitoring(ctx context.Context, events []*nomadApi.Events) (eventsProcessed int, err error) {
 	stream := make(chan *nomadApi.Events)
 	errChan := asynchronouslyMonitorEvaluation(stream)
-	return simulateNomadEventStream(stream, errChan, events)
+	return simulateNomadEventStream(ctx, stream, errChan, events)
 }
 
 func (s *MainTestSuite) TestApiClient_MonitorEvaluationWithSuccessfulEvent() {
@@ -306,7 +306,7 @@ func (s *MainTestSuite) TestApiClient_MonitorEvaluationWithSuccessfulEvent() {
 
 	for _, c := range cases {
 		s.Run(c.name, func() {
-			eventsProcessed, err := runEvaluationMonitoring(c.streamedEvents)
+			eventsProcessed, err := runEvaluationMonitoring(s.TestCtx, c.streamedEvents)
 			s.Nil(err)
 			s.Equal(c.expectedEventsProcessed, eventsProcessed)
 		})
@@ -347,7 +347,7 @@ func (s *MainTestSuite) TestApiClient_MonitorEvaluationWithFailingEvent() {
 
 	for _, c := range cases {
 		s.Run(c.name, func() {
-			eventsProcessed, err := runEvaluationMonitoring(c.streamedEvents)
+			eventsProcessed, err := runEvaluationMonitoring(s.TestCtx, c.streamedEvents)
 			s.Require().NotNil(err)
 			s.Contains(err.Error(), c.expectedError.Error())
 			s.Equal(c.expectedEventsProcessed, eventsProcessed)
@@ -363,7 +363,7 @@ func (s *MainTestSuite) TestApiClient_MonitorEvaluationFailsWhenFailingToDecodeE
 	}
 	_, err := event.Evaluation()
 	s.Require().NotNil(err)
-	eventsProcessed, err := runEvaluationMonitoring([]*nomadApi.Events{{Events: []nomadApi.Event{event}}})
+	eventsProcessed, err := runEvaluationMonitoring(s.TestCtx, []*nomadApi.Events{{Events: []nomadApi.Event{event}}})
 	s.Error(err)
 	s.Equal(1, eventsProcessed)
 }
@@ -431,7 +431,7 @@ func (s *MainTestSuite) TestApiClient_WatchAllocationsIgnoresOldAllocations() {
 		eventForAllocation(s.T(), oldRunningAllocation),
 	}}
 
-	assertWatchAllocation(s.T(), []*nomadApi.Events{&oldAllocationEvents},
+	assertWatchAllocation(s, []*nomadApi.Events{&oldAllocationEvents},
 		[]*nomadApi.Allocation(nil), []string(nil))
 }
 
@@ -446,7 +446,7 @@ func (s *MainTestSuite) TestApiClient_WatchAllocationsIgnoresUnhandledEvents() {
 			Type:  structs.TypeNodeEvent,
 		},
 	}}
-	assertWatchAllocation(s.T(), []*nomadApi.Events{&nodeEvents}, []*nomadApi.Allocation(nil), []string(nil))
+	assertWatchAllocation(s, []*nomadApi.Events{&nodeEvents}, []*nomadApi.Allocation(nil), []string(nil))
 }
 
 func (s *MainTestSuite) TestApiClient_WatchAllocationsUsesCallbacksForEvents() {
@@ -454,7 +454,7 @@ func (s *MainTestSuite) TestApiClient_WatchAllocationsUsesCallbacksForEvents() {
 	pendingEvents := nomadApi.Events{Events: []nomadApi.Event{eventForAllocation(s.T(), pendingAllocation)}}
 
 	s.Run("it does not add allocation when client status is pending", func() {
-		assertWatchAllocation(s.T(), []*nomadApi.Events{&pendingEvents}, []*nomadApi.Allocation(nil), []string(nil))
+		assertWatchAllocation(s, []*nomadApi.Events{&pendingEvents}, []*nomadApi.Allocation(nil), []string(nil))
 	})
 
 	startedAllocation := createRecentAllocation(structs.AllocClientStatusRunning, structs.AllocDesiredStatusRun)
@@ -463,12 +463,12 @@ func (s *MainTestSuite) TestApiClient_WatchAllocationsUsesCallbacksForEvents() {
 		eventForAllocation(s.T(), pendingAllocation), eventForAllocation(s.T(), startedAllocation)}}
 
 	s.Run("it adds allocation with matching events", func() {
-		assertWatchAllocation(s.T(), []*nomadApi.Events{&pendingStartedEvents},
+		assertWatchAllocation(s, []*nomadApi.Events{&pendingStartedEvents},
 			[]*nomadApi.Allocation{startedAllocation}, []string(nil))
 	})
 
 	s.Run("it skips heartbeat and adds allocation with matching events", func() {
-		assertWatchAllocation(s.T(), []*nomadApi.Events{&pendingStartedEvents},
+		assertWatchAllocation(s, []*nomadApi.Events{&pendingStartedEvents},
 			[]*nomadApi.Allocation{startedAllocation}, []string(nil))
 	})
 
@@ -481,23 +481,23 @@ func (s *MainTestSuite) TestApiClient_WatchAllocationsUsesCallbacksForEvents() {
 	}}
 
 	s.Run("it adds and deletes the allocation", func() {
-		assertWatchAllocation(s.T(), []*nomadApi.Events{&pendingStartStopEvents},
+		assertWatchAllocation(s, []*nomadApi.Events{&pendingStartStopEvents},
 			[]*nomadApi.Allocation{startedAllocation}, []string{stoppedAllocation.JobID})
 	})
 
 	s.Run("it ignores duplicate events", func() {
-		assertWatchAllocation(s.T(), []*nomadApi.Events{&pendingEvents, &startedEvents, &startedEvents,
+		assertWatchAllocation(s, []*nomadApi.Events{&pendingEvents, &startedEvents, &startedEvents,
 			&stoppedEvents, &stoppedEvents, &stoppedEvents},
 			[]*nomadApi.Allocation{startedAllocation}, []string{startedAllocation.JobID})
 	})
 
 	s.Run("it ignores events of unknown allocations", func() {
-		assertWatchAllocation(s.T(), []*nomadApi.Events{&startedEvents, &startedEvents,
+		assertWatchAllocation(s, []*nomadApi.Events{&startedEvents, &startedEvents,
 			&stoppedEvents, &stoppedEvents, &stoppedEvents}, []*nomadApi.Allocation(nil), []string(nil))
 	})
 
 	s.Run("it removes restarted allocations", func() {
-		assertWatchAllocation(s.T(), []*nomadApi.Events{&pendingStartedEvents, &pendingStartedEvents},
+		assertWatchAllocation(s, []*nomadApi.Events{&pendingStartedEvents, &pendingStartedEvents},
 			[]*nomadApi.Allocation{startedAllocation, startedAllocation}, []string{startedAllocation.JobID})
 	})
 
@@ -511,7 +511,7 @@ func (s *MainTestSuite) TestApiClient_WatchAllocationsUsesCallbacksForEvents() {
 		eventForAllocation(s.T(), rescheduleAllocation), eventForAllocation(s.T(), rescheduleStartedAllocation)}}
 
 	s.Run("it removes rescheduled allocations", func() {
-		assertWatchAllocation(s.T(), []*nomadApi.Events{&pendingStartedEvents, &rescheduleEvents},
+		assertWatchAllocation(s, []*nomadApi.Events{&pendingStartedEvents, &rescheduleEvents},
 			[]*nomadApi.Allocation{startedAllocation, rescheduleStartedAllocation}, []string{startedAllocation.JobID})
 	})
 
@@ -519,7 +519,7 @@ func (s *MainTestSuite) TestApiClient_WatchAllocationsUsesCallbacksForEvents() {
 	stoppedPendingEvents := nomadApi.Events{Events: []nomadApi.Event{eventForAllocation(s.T(), stoppedPendingAllocation)}}
 
 	s.Run("it removes stopped pending allocations", func() {
-		assertWatchAllocation(s.T(), []*nomadApi.Events{&pendingEvents, &stoppedPendingEvents},
+		assertWatchAllocation(s, []*nomadApi.Events{&pendingEvents, &stoppedPendingEvents},
 			[]*nomadApi.Allocation(nil), []string{stoppedPendingAllocation.JobID})
 	})
 
@@ -527,7 +527,7 @@ func (s *MainTestSuite) TestApiClient_WatchAllocationsUsesCallbacksForEvents() {
 	failedEvents := nomadApi.Events{Events: []nomadApi.Event{eventForAllocation(s.T(), failedAllocation)}}
 
 	s.Run("it removes stopped failed allocations", func() {
-		assertWatchAllocation(s.T(), []*nomadApi.Events{&pendingStartedEvents, &failedEvents},
+		assertWatchAllocation(s, []*nomadApi.Events{&pendingStartedEvents, &failedEvents},
 			[]*nomadApi.Allocation{startedAllocation}, []string{failedAllocation.JobID})
 	})
 
@@ -535,7 +535,7 @@ func (s *MainTestSuite) TestApiClient_WatchAllocationsUsesCallbacksForEvents() {
 	lostEvents := nomadApi.Events{Events: []nomadApi.Event{eventForAllocation(s.T(), lostAllocation)}}
 
 	s.Run("it removes stopped lost allocations", func() {
-		assertWatchAllocation(s.T(), []*nomadApi.Events{&pendingStartedEvents, &lostEvents},
+		assertWatchAllocation(s, []*nomadApi.Events{&pendingStartedEvents, &lostEvents},
 			[]*nomadApi.Allocation{startedAllocation}, []string{lostAllocation.JobID})
 	})
 
@@ -545,7 +545,7 @@ func (s *MainTestSuite) TestApiClient_WatchAllocationsUsesCallbacksForEvents() {
 		eventForAllocation(s.T(), rescheduledLostAllocation)}}
 
 	s.Run("it removes lost allocations not before the last restart attempt", func() {
-		assertWatchAllocation(s.T(), []*nomadApi.Events{&pendingStartedEvents, &rescheduledLostEvents},
+		assertWatchAllocation(s, []*nomadApi.Events{&pendingStartedEvents, &rescheduledLostEvents},
 			[]*nomadApi.Allocation{startedAllocation}, []string(nil))
 	})
 }
@@ -598,6 +598,80 @@ func (s *MainTestSuite) TestHandleAllocationEvent_IgnoresReschedulesForStoppedJo
 	s.False(ok)
 }
 
+func (s *MainTestSuite) TestHandleAllocationEvent_RegressionTest_14_09_2023() {
+	jobID := "29-6f04b525-5315-11ee-af32-fa163e079f19"
+	a1ID := "04d86250-550c-62f9-9a21-ecdc3b38773e"
+	a1Starting := createRecentAllocation(structs.AllocClientStatusPending, structs.AllocDesiredStatusRun)
+	a1Starting.ID = a1ID
+	a1Starting.JobID = jobID
+
+	// With this event the job is added to the idle runners
+	a1Running := createRecentAllocation(structs.AllocClientStatusRunning, structs.AllocDesiredStatusRun)
+	a1Running.ID = a1ID
+	a1Running.JobID = jobID
+
+	// With this event the job is removed from the idle runners
+	a2ID := "102f282f-376a-1453-4d3d-7d4e32046acd"
+	a2Starting := createRecentAllocation(structs.AllocClientStatusPending, structs.AllocDesiredStatusRun)
+	a2Starting.ID = a2ID
+	a2Starting.PreviousAllocation = a1ID
+	a2Starting.JobID = jobID
+
+	// Because the runner is neither an idle runner nor an used runner, this event triggered the now removed
+	// race condition handling that led to neither removing a2 from the allocations nor adding a3 to the allocations.
+	a3ID := "0d8a8ece-cf52-2968-5a9f-e972a4150a6e"
+	a3Starting := createRecentAllocation(structs.AllocClientStatusPending, structs.AllocDesiredStatusRun)
+	a3Starting.ID = a3ID
+	a3Starting.PreviousAllocation = a2ID
+	a3Starting.JobID = jobID
+
+	// a2Stopping was not ignored and led to an unexpected allocation stopping.
+	a2Stopping := createRecentAllocation(structs.AllocClientStatusPending, structs.AllocDesiredStatusStop)
+	a2Stopping.ID = a2ID
+	a2Stopping.PreviousAllocation = a1ID
+	a2Stopping.NextAllocation = a3ID
+	a2Stopping.JobID = jobID
+
+	// a2Complete was not ignored (wrong behavior).
+	a2Complete := createRecentAllocation(structs.AllocClientStatusComplete, structs.AllocDesiredStatusStop)
+	a2Complete.ID = a2ID
+	a2Complete.PreviousAllocation = a1ID
+	a2Complete.NextAllocation = a3ID
+	a2Complete.JobID = jobID
+
+	// a3Running was ignored because it was unknown (wrong behavior).
+	a3Running := createRecentAllocation(structs.AllocClientStatusRunning, structs.AllocDesiredStatusRun)
+	a3Running.ID = a3ID
+	a3Running.PreviousAllocation = a2ID
+	a3Running.JobID = jobID
+
+	events := []*nomadApi.Events{{Events: []nomadApi.Event{
+		eventForAllocation(s.T(), a1Starting),
+		eventForAllocation(s.T(), a1Running),
+		eventForAllocation(s.T(), a2Starting),
+		eventForAllocation(s.T(), a3Starting),
+		eventForAllocation(s.T(), a2Stopping),
+		eventForAllocation(s.T(), a2Complete),
+		eventForAllocation(s.T(), a3Running),
+	}}}
+
+	idleRunner := make(map[string]bool)
+	callbacks := &AllocationProcessing{
+		OnNew: func(alloc *nomadApi.Allocation, _ time.Duration) {
+			idleRunner[alloc.JobID] = true
+		},
+		OnDeleted: func(jobID string, _ error) bool {
+			_, ok := idleRunner[jobID]
+			delete(idleRunner, jobID)
+			return !ok
+		},
+	}
+
+	_, err := runAllocationWatching(s, events, callbacks)
+	s.NoError(err)
+	s.True(idleRunner[jobID])
+}
+
 func (s *MainTestSuite) TestHandleAllocationEvent_ReportsOOMKilledStatus() {
 	restartedAllocation := createRecentAllocation(structs.AllocClientStatusPending, structs.AllocDesiredStatusRun)
 	event := nomadApi.TaskEvent{Details: map[string]string{"oom_killed": "true"}}
@@ -641,21 +715,21 @@ func (s *MainTestSuite) TestAPIClient_WatchAllocations() {
 	s.Require().Error(err)
 
 	events := []*nomadApi.Events{{Events: []nomadApi.Event{event}}, {}}
-	eventsProcessed, err := runAllocationWatching(s.T(), events, noopAllocationProcessing)
+	eventsProcessed, err := runAllocationWatching(s, events, noopAllocationProcessing)
 	s.Error(err)
 	s.Equal(1, eventsProcessed)
 }
 
 func (s *MainTestSuite) TestAPIClient_WatchAllocationsReturnsErrorOnUnexpectedEOF() {
 	events := []*nomadApi.Events{{Err: ErrUnexpectedEOF}, {}}
-	eventsProcessed, err := runAllocationWatching(s.T(), events, noopAllocationProcessing)
+	eventsProcessed, err := runAllocationWatching(s, events, noopAllocationProcessing)
 	s.Error(err)
 	s.Equal(1, eventsProcessed)
 }
 
-func assertWatchAllocation(t *testing.T, events []*nomadApi.Events,
+func assertWatchAllocation(s *MainTestSuite, events []*nomadApi.Events,
 	expectedNewAllocations []*nomadApi.Allocation, expectedDeletedAllocations []string) {
-	t.Helper()
+	s.T().Helper()
 	var newAllocations []*nomadApi.Allocation
 	var deletedAllocations []string
 	callbacks := &AllocationProcessing{
@@ -668,23 +742,23 @@ func assertWatchAllocation(t *testing.T, events []*nomadApi.Events,
 		},
 	}
 
-	eventsProcessed, err := runAllocationWatching(t, events, callbacks)
-	assert.NoError(t, err)
-	assert.Equal(t, len(events), eventsProcessed)
+	eventsProcessed, err := runAllocationWatching(s, events, callbacks)
+	s.NoError(err)
+	s.Equal(len(events), eventsProcessed)
 
-	assert.Equal(t, expectedNewAllocations, newAllocations)
-	assert.Equal(t, expectedDeletedAllocations, deletedAllocations)
+	s.Equal(expectedNewAllocations, newAllocations)
+	s.Equal(expectedDeletedAllocations, deletedAllocations)
 }
 
 // runAllocationWatching simulates events streamed from the Nomad event stream
 // to the MonitorEvaluation method. It starts the MonitorEvaluation function as a goroutine
 // and sequentially transfers the events from the given array to a channel simulating the stream.
-func runAllocationWatching(t *testing.T, events []*nomadApi.Events, callbacks *AllocationProcessing) (
+func runAllocationWatching(s *MainTestSuite, events []*nomadApi.Events, callbacks *AllocationProcessing) (
 	eventsProcessed int, err error) {
-	t.Helper()
+	s.T().Helper()
 	stream := make(chan *nomadApi.Events)
 	errChan := asynchronouslyWatchAllocations(stream, callbacks)
-	return simulateNomadEventStream(stream, errChan, events)
+	return simulateNomadEventStream(s.TestCtx, stream, errChan, events)
 }
 
 // asynchronouslyMonitorEvaluation creates an APIClient with mocked Nomad API and