diff --git a/cmd/odek/audit_serve_test.go b/cmd/odek/audit_serve_test.go
index ec80784..17dc612 100644
--- a/cmd/odek/audit_serve_test.go
+++ b/cmd/odek/audit_serve_test.go
@@ -130,8 +130,7 @@ func TestAudit_WebSocketInvalidModelRejectedEarly(t *testing.T) {
 		t.Fatalf("session.NewStore: %v", err)
 	}
 	ln, mux := buildServeMux(t, store)
-	defer ln.Close()
-	go func() { _ = serveOnListener(ln, mux) }()
+	defer startServeTest(t, ln, mux)()
 	waitForHTTP(t, ln.Addr().String())
 
 	wsUpgradeLimiter.reset()
diff --git a/cmd/odek/next_security_vulnerabilities_test.go b/cmd/odek/next_security_vulnerabilities_test.go
index 9c35cd1..941d0bc 100644
--- a/cmd/odek/next_security_vulnerabilities_test.go
+++ b/cmd/odek/next_security_vulnerabilities_test.go
@@ -242,9 +242,8 @@ func TestServe_CSRF_AllowsLocalhostOrigin(t *testing.T) {
 func TestServe_API_RequiresServeToken(t *testing.T) {
 	store := newTestSessionStore(t)
 	ln, mux := buildServeMux(t, store)
-	defer ln.Close()
 
-	go serveOnListener(ln, mux)
+	defer startServeTest(t, ln, mux)()
 	waitForHTTP(t, ln.Addr().String())
 
 	resp, err := http.Get("http://" + ln.Addr().String() + "/api/sessions")
@@ -260,13 +259,12 @@ func TestServe_API_RequiresServeToken(t *testing.T) {
 func TestServe_API_RequiresLocalHost(t *testing.T) {
 	store := newTestSessionStore(t)
 	ln, mux := buildServeMux(t, store)
-	defer ln.Close()
 
 	testTokenMu.Lock()
 	token := testLastToken
 	testTokenMu.Unlock()
 
-	go serveOnListener(ln, mux)
+	defer startServeTest(t, ln, mux)()
 	waitForHTTP(t, ln.Addr().String())
 
 	req, _ := http.NewRequest(http.MethodGet, "http://"+ln.Addr().String()+"/api/sessions", nil)
@@ -285,13 +283,12 @@ func TestServe_API_RequiresLocalHost(t *testing.T) {
 func TestServe_API_AcceptsServeTokenHeader(t *testing.T) {
 	store := newTestSessionStore(t)
 	ln, mux := buildServeMux(t, store)
-	defer ln.Close()
 
 	testTokenMu.Lock()
 	token := testLastToken
 	testTokenMu.Unlock()
 
-	go serveOnListener(ln, mux)
+	defer startServeTest(t, ln, mux)()
 	waitForHTTP(t, ln.Addr().String())
 
 	req, _ := http.NewRequest(http.MethodGet, "http://"+ln.Addr().String()+"/api/sessions", nil)
@@ -309,13 +306,12 @@ func TestServe_API_AcceptsServeTokenHeader(t *testing.T) {
 func TestServe_API_AcceptsServeTokenCookie(t *testing.T) {
 	store := newTestSessionStore(t)
 	ln, mux := buildServeMux(t, store)
-	defer ln.Close()
 
 	testTokenMu.Lock()
 	token := testLastToken
 	testTokenMu.Unlock()
 
-	go serveOnListener(ln, mux)
+	defer startServeTest(t, ln, mux)()
 	waitForHTTP(t, ln.Addr().String())
 
 	req, _ := http.NewRequest(http.MethodGet, "http://"+ln.Addr().String()+"/api/sessions", nil)
diff --git a/cmd/odek/serve_api_test.go b/cmd/odek/serve_api_test.go
index 4f20a4b..68a5a65 100644
--- a/cmd/odek/serve_api_test.go
+++ b/cmd/odek/serve_api_test.go
@@ -885,9 +885,8 @@ func TestServe_E2E_NoRepetitiveResponses(t *testing.T) {
 
 	store := newTestSessionStore(t)
 	ln, mux := buildServeMux(t, store)
-	defer ln.Close()
 
-	go serveOnListener(ln, mux)
+	defer startServeTest(t, ln, mux)()
 	waitForHTTP(t, ln.Addr().String())
 
 	conn := dialTestWS(t, ln.Addr().String())
@@ -964,9 +963,8 @@ func TestServe_E2E_SessionMessagesStoredWithoutSystemInjections(t *testing.T) {
 
 	// Build a mux that also includes the session-by-ID route so we can inspect it.
 	ln, mux := buildServeMuxWithSessionByID(t, store)
-	defer ln.Close()
 
-	go serveOnListener(ln, mux)
+	defer startServeTest(t, ln, mux)()
 	waitForHTTP(t, ln.Addr().String())
 
 	conn := dialTestWS(t, ln.Addr().String())
diff --git a/cmd/odek/serve_api_v2_test.go b/cmd/odek/serve_api_v2_test.go
index f9940b7..68565a0 100644
--- a/cmd/odek/serve_api_v2_test.go
+++ b/cmd/odek/serve_api_v2_test.go
@@ -573,8 +573,7 @@ func TestServe_E2E_ServerInfoHelloAndPingPong(t *testing.T) {
 
 	store := newTestSessionStore(t)
 	ln, mux := buildServeMuxV2(t, store, nil)
-	defer ln.Close()
-	go func() { _ = serveOnListener(ln, mux) }()
+	defer startServeTest(t, ln, mux)()
 	waitForHTTP(t, ln.Addr().String())
 
 	wsUpgradeLimiter.reset()
@@ -613,8 +612,7 @@ func TestServe_E2E_ServerKeepalive(t *testing.T) {
 
 	store := newTestSessionStore(t)
 	ln, mux := buildServeMuxV2(t, store, nil)
-	defer ln.Close()
-	go func() { _ = serveOnListener(ln, mux) }()
+	defer startServeTest(t, ln, mux)()
 	waitForHTTP(t, ln.Addr().String())
 
 	wsUpgradeLimiter.reset()
@@ -644,8 +642,7 @@ func TestServe_E2E_SessionSwitchMessage(t *testing.T) {
 	}
 
 	ln, mux := buildServeMuxV2(t, store, nil)
-	defer ln.Close()
-	go func() { _ = serveOnListener(ln, mux) }()
+	defer startServeTest(t, ln, mux)()
 	waitForHTTP(t, ln.Addr().String())
 
 	wsUpgradeLimiter.reset()
@@ -684,8 +681,7 @@ func TestServe_E2E_WSCancelMessage(t *testing.T) {
 	}
 
 	ln, mux := buildServeMuxV2(t, store, nil)
-	defer ln.Close()
-	go func() { _ = serveOnListener(ln, mux) }()
+	defer startServeTest(t, ln, mux)()
 	waitForHTTP(t, ln.Addr().String())
 
 	wsUpgradeLimiter.reset()
@@ -729,8 +725,7 @@ func TestServe_E2E_StreamDeltas(t *testing.T) {
 	ln, mux := buildServeMuxV2(t, store, func(rc *config.ResolvedConfig) {
 		rc.Stream = true
 	})
-	defer ln.Close()
-	go func() { _ = serveOnListener(ln, mux) }()
+	defer startServeTest(t, ln, mux)()
 	waitForHTTP(t, ln.Addr().String())
 
 	wsUpgradeLimiter.reset()
@@ -796,8 +791,7 @@ func TestServe_E2E_StreamFallbackKeepsBulkPath(t *testing.T) {
 	ln, mux := buildServeMuxV2(t, store, func(rc *config.ResolvedConfig) {
 		rc.Stream = true
 	})
-	defer ln.Close()
-	go func() { _ = serveOnListener(ln, mux) }()
+	defer startServeTest(t, ln, mux)()
 	waitForHTTP(t, ln.Addr().String())
 
 	wsUpgradeLimiter.reset()
diff --git a/cmd/odek/serve_approval_test.go b/cmd/odek/serve_approval_test.go
index ad1749b..b5142a3 100644
--- a/cmd/odek/serve_approval_test.go
+++ b/cmd/odek/serve_approval_test.go
@@ -89,9 +89,8 @@ func TestServe_E2E_ApprovalRoundTrip(t *testing.T) {
 
 	store := newTestSessionStore(t)
 	ln, mux := buildServeMuxPromptAll(t, store)
-	defer ln.Close()
 
-	go func() { _ = serveOnListener(ln, mux) }()
+	defer startServeTest(t, ln, mux)()
 	waitForHTTP(t, ln.Addr().String())
 
 	conn := dialTestWS(t, ln.Addr().String())
diff --git a/cmd/odek/serve_buffer_bleed_test.go b/cmd/odek/serve_buffer_bleed_test.go
index e06e404..652a964 100644
--- a/cmd/odek/serve_buffer_bleed_test.go
+++ b/cmd/odek/serve_buffer_bleed_test.go
@@ -81,9 +81,7 @@ func TestServe_E2E_PromptPathSessionSwitch_ClearsStaleBuffer(t *testing.T) {
 	}
 
 	ln, mux := buildServeMux(t, store)
-	defer ln.Close()
-	errCh := make(chan error, 1)
-	go func() { errCh <- serveOnListener(ln, mux) }()
+	defer startServeTest(t, ln, mux)()
 	waitForHTTP(t, ln.Addr().String())
 
 	wsUpgradeLimiter.reset()
diff --git a/cmd/odek/serve_cancel_test.go b/cmd/odek/serve_cancel_test.go
index 06c418e..1c2cc7c 100644
--- a/cmd/odek/serve_cancel_test.go
+++ b/cmd/odek/serve_cancel_test.go
@@ -161,8 +161,7 @@ func TestServe_E2E_WSCancelInterruptsApprovalWait(t *testing.T) {
 
 	store := newTestSessionStore(t)
 	ln, mux := buildServeMuxPromptAll(t, store)
-	defer ln.Close()
-	go func() { _ = serveOnListener(ln, mux) }()
+	defer startServeTest(t, ln, mux)()
 	waitForHTTP(t, ln.Addr().String())
 
 	wsUpgradeLimiter.reset()
@@ -199,8 +198,7 @@ func TestServe_E2E_RESTCancelInterruptsApprovalWait(t *testing.T) {
 
 	store := newTestSessionStore(t)
 	ln, mux := buildServeMuxPromptAll(t, store)
-	defer ln.Close()
-	go func() { _ = serveOnListener(ln, mux) }()
+	defer startServeTest(t, ln, mux)()
 	waitForHTTP(t, ln.Addr().String())
 
 	wsUpgradeLimiter.reset()
@@ -335,8 +333,7 @@ func TestServe_E2E_WSCancelRunningPromptTerminalEvent(t *testing.T) {
 
 	store := newTestSessionStore(t)
 	ln, mux := buildServeMuxV2(t, store, nil)
-	defer ln.Close()
-	go func() { _ = serveOnListener(ln, mux) }()
+	defer startServeTest(t, ln, mux)()
 	waitForHTTP(t, ln.Addr().String())
 
 	wsUpgradeLimiter.reset()
@@ -384,8 +381,7 @@ func TestServe_E2E_ApprovalWorksAfterCancel(t *testing.T) {
 
 	store := newTestSessionStore(t)
 	ln, mux := buildServeMuxPromptAll(t, store)
-	defer ln.Close()
-	go func() { _ = serveOnListener(ln, mux) }()
+	defer startServeTest(t, ln, mux)()
 	waitForHTTP(t, ln.Addr().String())
 
 	wsUpgradeLimiter.reset()
@@ -491,9 +487,8 @@ func TestServe_E2E_CancelDuringSetupWindowHonored(t *testing.T) {
 	gate := &gatingResolver{entered: make(chan struct{}, 1), release: make(chan struct{})}
 	resReg := resource.NewRegistry(gate)
 	ln, mux := buildServeMuxWithResolvers(t, store, resReg)
-	defer ln.Close()
+	defer startServeTest(t, ln, mux)()
 	defer close(gate.release)
-	go func() { _ = serveOnListener(ln, mux) }()
 	waitForHTTP(t, ln.Addr().String())
 
 	wsUpgradeLimiter.reset()
diff --git a/cmd/odek/serve_lifecycle_test.go b/cmd/odek/serve_lifecycle_test.go
new file mode 100644
index 0000000..26206aa
--- /dev/null
+++ b/cmd/odek/serve_lifecycle_test.go
@@ -0,0 +1,31 @@
+package main
+
+import (
+	"errors"
+	"net"
+	"net/http"
+	"testing"
+	"time"
+)
+
+// startServeTest starts the real server and returns a stop function that waits
+// for its handlers and session writes to finish. Defer the returned function
+// before opening clients, so shutdown precedes environment and temp-dir cleanup.
+func startServeTest(t *testing.T, ln net.Listener, mux *http.ServeMux) func() {
+	t.Helper()
+	done := make(chan error, 1)
+	go func() { done <- serveOnListener(ln, mux) }()
+	return func() {
+		t.Helper()
+		http.DefaultClient.CloseIdleConnections()
+		_ = ln.Close()
+		select {
+		case err := <-done:
+			if err != nil && !errors.Is(err, net.ErrClosed) {
+				t.Errorf("serve shutdown: %v", err)
+			}
+		case <-time.After(20 * time.Second):
+			t.Fatal("serve shutdown did not finish before test cleanup")
+		}
+	}
+}
diff --git a/cmd/odek/serve_surface_fixes_test.go b/cmd/odek/serve_surface_fixes_test.go
index 7208af8..cc54d32 100644
--- a/cmd/odek/serve_surface_fixes_test.go
+++ b/cmd/odek/serve_surface_fixes_test.go
@@ -272,8 +272,7 @@ func TestServe_E2E_PingPongUsesConfigSnapshotNotLiveModel(t *testing.T) {
 
 	store := newTestSessionStore(t)
 	ln, mux := buildServeMuxV2(t, store, func(rc *config.ResolvedConfig) { rc.Model = "initial-model" })
-	defer ln.Close()
-	go func() { _ = serveOnListener(ln, mux) }()
+	defer startServeTest(t, ln, mux)()
 	waitForHTTP(t, ln.Addr().String())
 
 	wsUpgradeLimiter.reset()
diff --git a/cmd/odek/serve_test.go b/cmd/odek/serve_test.go
index d2a658f..0a5e8c5 100644
--- a/cmd/odek/serve_test.go
+++ b/cmd/odek/serve_test.go
@@ -6,7 +6,6 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
-	"io/fs"
 	"net"
 	"net/http"
 	"net/http/httptest"
@@ -583,34 +582,8 @@ func TestServe_E2E_WebSocketPipeline(t *testing.T) {
 	mux.HandleFunc("/api/resources", handleResourceSearch(resourceReg))
 	mux.HandleFunc("/api/sessions", handleSessionList(store))
 
-	// Start serving on the pre-created listener in a goroutine
-	errCh := make(chan error, 1)
-	go func() {
-		errCh <- serveOnListener(ln, mux)
-	}()
-	defer ln.Close()
-
-	// Wait for server to be ready
-	var httpReady bool
-	for i := 0; i < 20; i++ {
-		time.Sleep(250 * time.Millisecond)
-		resp, err := http.Get("http://" + addr + "/")
-		if err == nil && resp.StatusCode == 200 {
-			resp.Body.Close()
-			httpReady = true
-			break
-		}
-	}
-	if !httpReady {
-		// Check if serveCmd returned an error immediately
-		select {
-		case err := <-errCh:
-			t.Fatalf("server exited before ready: %v", err)
-		default:
-			t.Fatal("server not ready after 5s")
-		}
-	}
-	defer ln.Close()
+	defer startServeTest(t, ln, mux)()
+	waitForHTTP(t, addr)
 
 	// 1. Connect via WebSocket
 	// Reset the per-IP upgrade limiter so this E2E test is not throttled by
@@ -703,13 +676,9 @@ func TestServe_E2E_FullWebUIFlow(t *testing.T) {
 
 	// 4. Build the real odek serve mux with mock config
 	ln, mux := buildServeMux(t, store)
-	defer ln.Close()
 
 	// 5. Start serving
-	errCh := make(chan error, 1)
-	go func() {
-		errCh <- serveOnListener(ln, mux)
-	}()
+	defer startServeTest(t, ln, mux)()
 
 	// 6. Wait for HTTP ready
 	waitForHTTP(t, ln.Addr().String())
@@ -851,37 +820,6 @@ func newTestSessionStore(t *testing.T) *session.Store {
 	return store
 }
 
-// waitForOdekTreeQuiet blocks until a write newer than `since` has been seen
-// under dir and no file has been modified for quietWindow (bounded by
-// timeout). The serve handler issues its final store.Save — session file plus
-// vector-index files — and runs the learn loop AFTER sending the "done"
-// event (serve.go), so a test that returns on "done" can race those writes
-// and fail t.TempDir cleanup with "directory not empty". Best-effort: a
-// timeout is not a test failure.
-func waitForOdekTreeQuiet(dir string, since time.Time, quietWindow, timeout time.Duration) {
-	deadline := time.Now().Add(timeout)
-	sawWrite := false
-	for {
-		var latest time.Time
-		_ = filepath.WalkDir(dir, func(_ string, d fs.DirEntry, err error) error {
-			if err != nil || d.IsDir() {
-				return nil
-			}
-			if fi, err := d.Info(); err == nil && fi.ModTime().After(latest) {
-				latest = fi.ModTime()
-			}
-			return nil
-		})
-		if latest.After(since) {
-			sawWrite = true
-		}
-		if (sawWrite && time.Since(latest) >= quietWindow) || time.Now().After(deadline) {
-			return
-		}
-		time.Sleep(50 * time.Millisecond)
-	}
-}
-
 // mockLLM creates an httptest.Server that handles both the model discovery call
 // (GET /models — called once by odek.New during agent initialization) and chat
 // completion requests. The chat handler receives a 1-based callCount that
@@ -1248,10 +1186,8 @@ func TestServe_E2E_MultiToolCall(t *testing.T) {
 
 	store := newTestSessionStore(t)
 	ln, mux := buildServeMux(t, store)
-	defer ln.Close()
 
-	errCh := make(chan error, 1)
-	go func() { errCh <- serveOnListener(ln, mux) }()
+	defer startServeTest(t, ln, mux)()
 	waitForHTTP(t, ln.Addr().String())
 
 	conn := dialTestWS(t, ln.Addr().String())
@@ -1369,10 +1305,8 @@ func TestServe_E2E_TokenStats(t *testing.T) {
 
 	store := newTestSessionStore(t)
 	ln, mux := buildServeMux(t, store)
-	defer ln.Close()
 
-	errCh := make(chan error, 1)
-	go func() { errCh <- serveOnListener(ln, mux) }()
+	defer startServeTest(t, ln, mux)()
 	waitForHTTP(t, ln.Addr().String())
 
 	conn := dialTestWS(t, ln.Addr().String())
@@ -1482,7 +1416,6 @@ statsCheck:
 
 	conn.SetReadDeadline(time.Now().Add(15 * time.Second))
 	var done2 map[string]any
-	var done2At time.Time
 	for i := 0; i < 15; i++ {
 		var raw []byte
 		if err := golangws.Message.Receive(conn, &raw); err != nil {
@@ -1496,7 +1429,6 @@ statsCheck:
 		}
 		if evt["type"] == "done" {
 			done2 = evt
-			done2At = time.Now()
 			goto sessionCheck
 		}
 		if evt["type"] == "error" {
@@ -1506,10 +1438,6 @@ statsCheck:
 	t.Fatal("did not receive second done event")
 
 sessionCheck:
-	// The final store.Save runs after "done" is sent — wait for the writes
-	// to settle so t.TempDir cleanup doesn't race them.
-	waitForOdekTreeQuiet(filepath.Join(os.Getenv("HOME"), ".odek"), done2At, 300*time.Millisecond, 10*time.Second)
-
 	if done2 == nil {
 		t.Fatal("second done event not found")
 	}
@@ -1563,10 +1491,8 @@ func TestServe_E2E_UsageEvents(t *testing.T) {
 
 	store := newTestSessionStore(t)
 	ln, mux := buildServeMux(t, store)
-	defer ln.Close()
 
-	errCh := make(chan error, 1)
-	go func() { errCh <- serveOnListener(ln, mux) }()
+	defer startServeTest(t, ln, mux)()
 	waitForHTTP(t, ln.Addr().String())
 
 	conn := dialTestWS(t, ln.Addr().String())
@@ -1580,7 +1506,6 @@ func TestServe_E2E_UsageEvents(t *testing.T) {
 
 	conn.SetReadDeadline(time.Now().Add(15 * time.Second))
 	var usages []map[string]any
-	var doneAt time.Time
 	for i := 0; i < 20; i++ {
 		var raw []byte
 		if err := golangws.Message.Receive(conn, &raw); err != nil {
@@ -1596,7 +1521,6 @@ func TestServe_E2E_UsageEvents(t *testing.T) {
 		case "usage":
 			usages = append(usages, evt)
 		case "done":
-			doneAt = time.Now()
 			goto usageCheck
 		case "error":
 			t.Fatalf("unexpected error: %v", evt["message"])
@@ -1605,11 +1529,6 @@ func TestServe_E2E_UsageEvents(t *testing.T) {
 	t.Fatal("did not receive done event")
 
 usageCheck:
-	// The final store.Save (session file + vector index) and the learn loop
-	// run after "done" is sent — wait for those writes to settle so
-	// t.TempDir cleanup doesn't race them ("directory not empty").
-	waitForOdekTreeQuiet(filepath.Join(os.Getenv("HOME"), ".odek"), doneAt, 300*time.Millisecond, 10*time.Second)
-
 	if len(usages) < 2 {
 		t.Fatalf("got %d usage events before done, want at least 2 (one per LLM turn)", len(usages))
 	}
@@ -1652,10 +1571,8 @@ func TestServe_E2E_LiveToolEvents(t *testing.T) {
 
 	store := newTestSessionStore(t)
 	ln, mux := buildServeMux(t, store)
-	defer ln.Close()
 
-	errCh := make(chan error, 1)
-	go func() { errCh <- serveOnListener(ln, mux) }()
+	defer startServeTest(t, ln, mux)()
 	waitForHTTP(t, ln.Addr().String())
 
 	conn := dialTestWS(t, ln.Addr().String())
@@ -1671,7 +1588,6 @@ func TestServe_E2E_LiveToolEvents(t *testing.T) {
 
 	var toolCallTime, toolResultTime, doneTime int
 	var eventOrder []string
-	var doneAt time.Time
 
 	// Additive protocol frames may precede done; the read deadline bounds the wait.
 	for i := 0; i < 100; i++ {
@@ -1699,7 +1615,6 @@ func TestServe_E2E_LiveToolEvents(t *testing.T) {
 			}
 		case "done":
 			doneTime = i
-			doneAt = time.Now()
 			goto doneCheck
 		case "error":
 			t.Fatalf("unexpected error: %v", evt["message"])
@@ -1707,10 +1622,6 @@ func TestServe_E2E_LiveToolEvents(t *testing.T) {
 	}
 
 doneCheck:
-	// The final store.Save runs after "done" is sent — wait for the writes
-	// to settle so t.TempDir cleanup doesn't race them.
-	waitForOdekTreeQuiet(filepath.Join(os.Getenv("HOME"), ".odek"), doneAt, 300*time.Millisecond, 10*time.Second)
-
 	t.Logf("Event order: %v", eventOrder)
 
 	if toolCallTime == 0 {
@@ -2024,11 +1935,10 @@ func TestServe_E2E_CancelWithMockLLM(t *testing.T) {
 
 	store := newTestSessionStore(t)
 	ln, mux := buildServeMux(t, store)
-	defer ln.Close()
 
-	errCh := make(chan error, 1)
-	go func() { errCh <- serveOnListener(ln, mux) }()
+	defer startServeTest(t, ln, mux)()
 	waitForHTTP(t, ln.Addr().String())
+	wsUpgradeLimiter.reset()
 
 	conn := dialTestWS(t, ln.Addr().String())
 	defer conn.Close()
@@ -2153,11 +2063,10 @@ func TestServe_Cancel_CannotCrossSessions(t *testing.T) {
 
 	store := newTestSessionStore(t)
 	ln, mux := buildServeMux(t, store)
-	defer ln.Close()
 
-	errCh := make(chan error, 1)
-	go func() { errCh <- serveOnListener(ln, mux) }()
+	defer startServeTest(t, ln, mux)()
 	waitForHTTP(t, ln.Addr().String())
+	wsUpgradeLimiter.reset()
 
 	// Victim connection: starts first, hits the slow LLM path.
 	victimConn := dialTestWS(t, ln.Addr().String())
@@ -2375,12 +2284,8 @@ func TestServe_E2E_AttachmentsWrappedAsUntrusted(t *testing.T) {
 
 	store := newTestSessionStore(t)
 	ln, mux := buildServeMux(t, store)
-	defer ln.Close()
 
-	errCh := make(chan error, 1)
-	go func() {
-		errCh <- serveOnListener(ln, mux)
-	}()
+	defer startServeTest(t, ln, mux)()
 	waitForHTTP(t, ln.Addr().String())
 
 	conn := dialTestWS(t, ln.Addr().String())
@@ -2467,10 +2372,8 @@ func TestServe_E2E_AttachmentsWrappedAsUntrusted(t *testing.T) {
 func TestServe_CSRF_TokenRequired(t *testing.T) {
 	store := newTestSessionStore(t)
 	ln, mux := buildServeMux(t, store)
-	defer ln.Close()
 
-	errCh := make(chan error, 1)
-	go func() { errCh <- serveOnListener(ln, mux) }()
+	defer startServeTest(t, ln, mux)()
 	waitForHTTP(t, ln.Addr().String())
 
 	addr := ln.Addr().String()
@@ -2565,10 +2468,8 @@ func TestServe_E2E_PromptSizeCap(t *testing.T) {
 
 	store := newTestSessionStore(t)
 	ln, mux := buildServeMux(t, store)
-	defer ln.Close()
 
-	errCh := make(chan error, 1)
-	go func() { errCh <- serveOnListener(ln, mux) }()
+	defer startServeTest(t, ln, mux)()
 	waitForHTTP(t, ln.Addr().String())
 
 	conn := dialTestWS(t, ln.Addr().String())
@@ -2616,10 +2517,8 @@ func TestServe_E2E_InvalidModelIDRejected(t *testing.T) {
 
 	store := newTestSessionStore(t)
 	ln, mux := buildServeMux(t, store)
-	defer ln.Close()
 
-	errCh := make(chan error, 1)
-	go func() { errCh <- serveOnListener(ln, mux) }()
+	defer startServeTest(t, ln, mux)()
 	waitForHTTP(t, ln.Addr().String())
 
 	conn := dialTestWS(t, ln.Addr().String())
diff --git a/cmd/odek/turn_started_test.go b/cmd/odek/turn_started_test.go
index e3efe1b..e48727b 100644
--- a/cmd/odek/turn_started_test.go
+++ b/cmd/odek/turn_started_test.go
@@ -88,8 +88,7 @@ func startTurnServer(t *testing.T) *golangws.Conn {
 
 	store := newTestSessionStore(t)
 	ln, mux := buildServeMuxV2(t, store, nil)
-	t.Cleanup(func() { ln.Close() })
-	go func() { _ = serveOnListener(ln, mux) }()
+	t.Cleanup(startServeTest(t, ln, mux))
 	waitForHTTP(t, ln.Addr().String())
 
 	wsUpgradeLimiter.reset()