diff --git a/internal/client/storage.go b/internal/client/storage.go
index fbbfd1b8..e3bf58e0 100644
--- a/internal/client/storage.go
+++ b/internal/client/storage.go
@@ -17,6 +17,7 @@ import (
 	"github.com/AdguardTeam/golibs/errors"
 	"github.com/AdguardTeam/golibs/hostsfile"
 	"github.com/AdguardTeam/golibs/logutil/slogutil"
+	"github.com/AdguardTeam/golibs/timeutil"
 )
 
 // allowedTags is the list of available client tags.
@@ -89,6 +90,10 @@ type StorageConfig struct {
 	// not be nil.
 	Logger *slog.Logger
 
+	// Clock is used by [upstreamManager] to retrieve the current time.  It must
+	// not be nil.
+	Clock timeutil.Clock
+
 	// DHCP is used to match IPs against MACs of persistent clients and update
 	// [SourceDHCP] runtime client information.  It must not be nil.
 	DHCP DHCP
@@ -167,7 +172,7 @@ func NewStorage(ctx context.Context, conf *StorageConfig) (s *Storage, err error
 		mu:                     &sync.Mutex{},
 		index:                  newIndex(),
 		runtimeIndex:           newRuntimeIndex(),
-		upstreamManager:        newUpstreamManager(conf.Logger),
+		upstreamManager:        newUpstreamManager(conf.Logger, conf.Clock),
 		dhcp:                   conf.DHCP,
 		etcHosts:               conf.EtcHosts,
 		arpDB:                  conf.ARPDB,
diff --git a/internal/client/storage_test.go b/internal/client/storage_test.go
index 4a981148..d00f8350 100644
--- a/internal/client/storage_test.go
+++ b/internal/client/storage_test.go
@@ -18,17 +18,20 @@ import (
 	"github.com/AdguardTeam/golibs/hostsfile"
 	"github.com/AdguardTeam/golibs/logutil/slogutil"
 	"github.com/AdguardTeam/golibs/testutil"
+	"github.com/AdguardTeam/golibs/testutil/faketime"
+	"github.com/AdguardTeam/golibs/timeutil"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
 
 // newTestStorage is a helper function that returns initialized storage.
-func newTestStorage(tb testing.TB) (s *client.Storage) {
+func newTestStorage(tb testing.TB, clock timeutil.Clock) (s *client.Storage) {
 	tb.Helper()
 
 	ctx := testutil.ContextWithTimeout(tb, testTimeout)
 	s, err := client.NewStorage(ctx, &client.StorageConfig{
 		Logger: slogutil.NewDiscardLogger(),
+		Clock:  clock,
 	})
 	require.NoError(tb, err)
 
@@ -695,7 +698,7 @@ func TestStorage_Add(t *testing.T) {
 	}
 
 	ctx := testutil.ContextWithTimeout(t, testTimeout)
-	s := newTestStorage(t)
+	s := newTestStorage(t, timeutil.SystemClock{})
 	tags := s.AllowedTags()
 	require.NotZero(t, len(tags))
 	require.True(t, slices.IsSorted(tags))
@@ -826,7 +829,7 @@ func TestStorage_RemoveByName(t *testing.T) {
 	}
 
 	ctx := testutil.ContextWithTimeout(t, testTimeout)
-	s := newTestStorage(t)
+	s := newTestStorage(t, timeutil.SystemClock{})
 	err := s.Add(ctx, existingClient)
 	require.NoError(t, err)
 
@@ -851,7 +854,7 @@ func TestStorage_RemoveByName(t *testing.T) {
 	}
 
 	t.Run("duplicate_remove", func(t *testing.T) {
-		s = newTestStorage(t)
+		s = newTestStorage(t, timeutil.SystemClock{})
 		err = s.Add(ctx, existingClient)
 		require.NoError(t, err)
 
@@ -1308,7 +1311,16 @@ func TestStorage_CustomUpstreamConfig(t *testing.T) {
 		Upstreams: []string{"192.0.2.0"},
 	}
 
-	s := newTestStorage(t)
+	date := time.Now()
+	clock := &faketime.Clock{
+		OnNow: func() (now time.Time) {
+			date = date.Add(time.Second)
+
+			return date
+		},
+	}
+
+	s := newTestStorage(t, clock)
 	s.UpdateCommonUpstreamConfig(&client.CommonUpstreamConfig{
 		UpstreamTimeout: testUpstreamTimeout,
 	})
diff --git a/internal/client/upstreammanager.go b/internal/client/upstreammanager.go
index bc2c4362..f6cad878 100644
--- a/internal/client/upstreammanager.go
+++ b/internal/client/upstreammanager.go
@@ -12,6 +12,7 @@ import (
 	"github.com/AdguardTeam/golibs/errors"
 	"github.com/AdguardTeam/golibs/logutil/slogutil"
 	"github.com/AdguardTeam/golibs/stringutil"
+	"github.com/AdguardTeam/golibs/timeutil"
 )
 
 // CommonUpstreamConfig contains common settings for custom client upstream
@@ -68,16 +69,20 @@ type upstreamManager struct {
 	// commonConf is the common upstream configuration.
 	commonConf *CommonUpstreamConfig
 
+	// clock is used to get the current time.  It must not be nil.
+	clock timeutil.Clock
+
 	// confUpdate is the timestamp of the latest common upstream configuration
 	// update.
 	confUpdate time.Time
 }
 
 // newUpstreamManager returns the new properly initialized upstream manager.
-func newUpstreamManager(logger *slog.Logger) (m *upstreamManager) {
+func newUpstreamManager(logger *slog.Logger, clock timeutil.Clock) (m *upstreamManager) {
 	return &upstreamManager{
 		logger:          logger,
 		uidToCustomConf: make(map[UID]*customUpstreamConfig),
+		clock:           clock,
 	}
 }
 
@@ -85,7 +90,7 @@ func newUpstreamManager(logger *slog.Logger) (m *upstreamManager) {
 // timestamp of the latest configuration update.
 func (m *upstreamManager) updateCommonUpstreamConfig(conf *CommonUpstreamConfig) {
 	m.commonConf = conf
-	m.confUpdate = time.Now()
+	m.confUpdate = m.clock.Now()
 }
 
 // updateCustomUpstreamConfig updates the stored custom client upstream
diff --git a/internal/home/clients.go b/internal/home/clients.go
index e2fd62fb..4a5a4d00 100644
--- a/internal/home/clients.go
+++ b/internal/home/clients.go
@@ -19,6 +19,7 @@ import (
 	"github.com/AdguardTeam/AdGuardHome/internal/whois"
 	"github.com/AdguardTeam/golibs/errors"
 	"github.com/AdguardTeam/golibs/logutil/slogutil"
+	"github.com/AdguardTeam/golibs/timeutil"
 )
 
 // clientsContainer is the storage of all runtime and persistent clients.
@@ -106,6 +107,7 @@ func (clients *clientsContainer) Init(
 
 	clients.storage, err = client.NewStorage(ctx, &client.StorageConfig{
 		Logger:                 baseLogger.With(slogutil.KeyPrefix, "client_storage"),
+		Clock:                  timeutil.SystemClock{},
 		InitialClients:         confClients,
 		DHCP:                   dhcpServer,
 		EtcHosts:               hosts,