diff --git a/splitter/nicehash/impl.go b/splitter/nicehash/impl.go
index a96f7a8..001f466 100644
--- a/splitter/nicehash/impl.go
+++ b/splitter/nicehash/impl.go
@@ -290,6 +290,7 @@ func (m *NonceMapper) OnResultAccepted(sequence int64, accepted bool, errorMessa
 	job := m.storage.job
 	prevJob := m.storage.prevJob
 	m.storage.mu.Unlock()
+	_ = m.storage.IsValidJobID(ctx.JobID)
 	expired := ctx.JobID != "" && ctx.JobID == prevJob.JobID && ctx.JobID != job.JobID
 	m.mu.Unlock()
 	if !ok || miner == nil {
@@ -400,7 +401,17 @@ func (s *NonceStorage) IsValidJobID(id string) bool {
 	}
 	s.mu.Lock()
 	defer s.mu.Unlock()
-	return id != "" && (id == s.job.JobID || id == s.prevJob.JobID)
+	if id == "" {
+		return false
+	}
+	if id == s.job.JobID {
+		return true
+	}
+	if id == s.prevJob.JobID && s.prevJob.JobID != "" {
+		s.expired++
+		return true
+	}
+	return false
 }
 
 // SlotCount returns free, dead, and active counts.
diff --git a/splitter/nicehash/storage.go b/splitter/nicehash/storage.go
index da36e3a..a97d24d 100644
--- a/splitter/nicehash/storage.go
+++ b/splitter/nicehash/storage.go
@@ -20,6 +20,7 @@ type NonceStorage struct {
 	miners  map[int64]*proxy.Miner // minerID → Miner pointer for active miners
 	job     proxy.Job              // current job from pool
 	prevJob proxy.Job              // previous job (for stale submit validation)
-	cursor  int                    // search starts here (round-robin allocation)
+	expired uint64
+	cursor  int // search starts here (round-robin allocation)
 	mu      sync.Mutex
 }
diff --git a/splitter/nicehash/storage_test.go b/splitter/nicehash/storage_test.go
index 9805a0a..ab5da9a 100644
--- a/splitter/nicehash/storage_test.go
+++ b/splitter/nicehash/storage_test.go
@@ -24,3 +24,22 @@ func TestNonceStorage_AddAndRemove(t *testing.T) {
 		t.Fatalf("unexpected slot counts: free=%d dead=%d active=%d", free, dead, active)
 	}
 }
+
+func TestNonceStorage_IsValidJobID_Ugly(t *testing.T) {
+	storage := NewNonceStorage()
+	storage.job = proxy.Job{JobID: "job-2"}
+	storage.prevJob = proxy.Job{JobID: "job-1"}
+
+	if !storage.IsValidJobID("job-2") {
+		t.Fatalf("expected current job to be valid")
+	}
+	if !storage.IsValidJobID("job-1") {
+		t.Fatalf("expected previous job to remain valid")
+	}
+	if storage.expired != 1 {
+		t.Fatalf("expected one expired job validation, got %d", storage.expired)
+	}
+	if storage.IsValidJobID("") {
+		t.Fatalf("expected empty job id to be invalid")
+	}
+}
diff --git a/splitter/simple/impl.go b/splitter/simple/impl.go
index f76fdd8..e7b945f 100644
--- a/splitter/simple/impl.go
+++ b/splitter/simple/impl.go
@@ -53,10 +53,11 @@ func (s *SimpleSplitter) OnLogin(event *proxy.LoginEvent) {
 	}
 	s.mu.Lock()
 	defer s.mu.Unlock()
+	now := time.Now()
 
 	if s.cfg.ReuseTimeout > 0 {
 		for id, mapper := range s.idle {
-			if mapper.strategy != nil && mapper.strategy.IsActive() {
+			if mapper.strategy != nil && mapper.strategy.IsActive() && !mapper.idleAt.IsZero() && now.Sub(mapper.idleAt) <= time.Duration(s.cfg.ReuseTimeout)*time.Second {
 				delete(s.idle, id)
 				mapper.miner = event.Miner
 				mapper.idleAt = time.Time{}
diff --git a/splitter/simple/impl_test.go b/splitter/simple/impl_test.go
index 78e3557..5fac90e 100644
--- a/splitter/simple/impl_test.go
+++ b/splitter/simple/impl_test.go
@@ -2,6 +2,7 @@ package simple
 
 import (
 	"testing"
+	"time"
 
 	"dappco.re/go/proxy"
 	"dappco.re/go/proxy/pool"
@@ -24,6 +25,7 @@ func TestSimpleSplitter_OnLogin_Good(t *testing.T) {
 		id:         7,
 		strategy:   activeStrategy{},
 		currentJob: job,
+		idleAt:     time.Now(),
 	}
 	splitter.idle[mapper.id] = mapper
 
@@ -36,3 +38,31 @@ func TestSimpleSplitter_OnLogin_Good(t *testing.T) {
 		t.Fatalf("expected current job to be restored on reuse, got %q", got)
 	}
 }
+
+func TestSimpleSplitter_OnLogin_Ugly(t *testing.T) {
+	splitter := NewSimpleSplitter(&proxy.Config{ReuseTimeout: 30}, nil, func(listener pool.StratumListener) pool.Strategy {
+		return activeStrategy{}
+	})
+	miner := &proxy.Miner{}
+	expired := &SimpleMapper{
+		id:       7,
+		strategy: activeStrategy{},
+		idleAt:   time.Now().Add(-time.Minute),
+	}
+	splitter.idle[expired.id] = expired
+
+	splitter.OnLogin(&proxy.LoginEvent{Miner: miner})
+
+	if miner.RouteID() == expired.id {
+		t.Fatalf("expected expired mapper not to be reclaimed")
+	}
+	if miner.RouteID() != 0 {
+		t.Fatalf("expected a new mapper to be allocated, got route id %d", miner.RouteID())
+	}
+	if len(splitter.active) != 1 {
+		t.Fatalf("expected one active mapper, got %d", len(splitter.active))
+	}
+	if len(splitter.idle) != 1 {
+		t.Fatalf("expected expired mapper to remain idle until GC, got %d idle mappers", len(splitter.idle))
+	}
+}