diff --git a/internal/ui/compose_test.go b/internal/ui/compose_test.go
index 6d334dd..10f6961 100644
--- a/internal/ui/compose_test.go
+++ b/internal/ui/compose_test.go
@@ -86,7 +86,8 @@ func TestComposeSuggestions_MultiRecipientInsert(t *testing.T) {
 // Sending must persist user-typed "Name <addr>" recipients into the contacts
 // store so autocomplete knows them next time (no contacts file needed).
 func TestHarvestTypedRecipients(t *testing.T) {
-	s := contacts.Load(filepath.Join(t.TempDir(), "contacts"))
+	cachePath := filepath.Join(t.TempDir(), "contacts")
+	s := contacts.Load(cachePath)
 	m := Model{contacts: s}
 	m.harvestTypedRecipients(
 		"Max Muster <max@muster.example>, bare@x.io",
@@ -109,4 +110,8 @@ func TestHarvestTypedRecipients(t *testing.T) {
 	// Nil store: must be a no-op, not a panic.
 	nilModel := Model{}
 	nilModel.harvestTypedRecipients("A <a@b.io>")
+
+	// harvestTypedRecipients persists via safeGo(SaveIfDirty) — wait for
+	// the write before TempDir cleanup runs.
+	waitForFile(t, cachePath)
 }
diff --git a/internal/ui/helpers_test.go b/internal/ui/helpers_test.go
new file mode 100644
index 0000000..0af3dd4
--- /dev/null
+++ b/internal/ui/helpers_test.go
@@ -0,0 +1,25 @@
+package ui
+
+import (
+	"os"
+	"testing"
+	"time"
+)
+
+// waitForFile blocks until path exists on disk. Tests that trigger async
+// persistence (safeGo → Save) into a t.TempDir must call this before
+// returning: the test's TempDir cleanup otherwise races the goroutine and
+// fails with "unlinkat … directory not empty" (flaky under -count / -race).
+func waitForFile(t *testing.T, path string) {
+	t.Helper()
+	deadline := time.Now().Add(2 * time.Second)
+	for {
+		if _, err := os.Stat(path); err == nil {
+			return
+		}
+		if !time.Now().Before(deadline) {
+			t.Fatalf("%s never landed on disk", path)
+		}
+		time.Sleep(2 * time.Millisecond)
+	}
+}
diff --git a/internal/ui/model_test.go b/internal/ui/model_test.go
index 45fc3a8..b3e9390 100644
--- a/internal/ui/model_test.go
+++ b/internal/ui/model_test.go
@@ -1300,6 +1300,9 @@ func TestApplySenderRules_PersistsMatches(t *testing.T) {
 	if n := m.applySenderRules(emails); n != 1 {
 		t.Errorf("applySenderRules = %d, want 1", n)
 	}
+	// applySenderRules persists via safeGo(store.Save) — wait for the
+	// write before TempDir cleanup runs.
+	waitForFile(t, path)
 	if title, ok := s.TitleOf("<new1>"); !ok || title != "Bounces" {
 		t.Errorf("<new1> should now belong to Bounces, got %q %v", title, ok)
 	}