diff --git a/api/auth/center.go b/api/auth/center.go
index 09733738..fdb3b25c 100644
--- a/api/auth/center.go
+++ b/api/auth/center.go
@@ -40,6 +40,9 @@ var (
 	postPolicyCredentialRegexp = regexp.MustCompile(`(?P<access_key_id>[^/]+)/(?P<date>[^/]+)/(?P<region>[^/]*)/(?P<service>[^/]+)/aws4_request`)
 )
 
+// need for tests.
+var timeNow = time.Now
+
 type (
 	Center struct {
 		reg                        *RegexpSubmatcher
@@ -470,7 +473,7 @@ func (c *Center) checkSign(ctx context.Context, authHeader *AuthHeader, box *acc
 }
 
 func checkPresignedDate(authHeader *AuthHeader, signatureDateTime time.Time) error {
-	now := time.Now()
+	now := timeNow()
 	if signatureDateTime.Add(authHeader.Expiration).Before(now) {
 		return fmt.Errorf("%w: expired: now %s, signature %s", apierr.GetAPIError(apierr.ErrExpiredPresignRequest),
 			now.Format(time.RFC3339), signatureDateTime.Format(time.RFC3339))
diff --git a/api/auth/center_test.go b/api/auth/center_test.go
index 94936c21..0b9f9cc7 100644
--- a/api/auth/center_test.go
+++ b/api/auth/center_test.go
@@ -182,6 +182,71 @@ func TestSignatureV4(t *testing.T) {
 	require.Equal(t, signature, signatureComputed, "signature mismatched")
 }
 
+func TestSignExpectHeader(t *testing.T) {
+	timeNow = func() time.Time {
+		return time.Date(2025, 3, 10, 11, 0, 0, 0, time.UTC)
+	}
+	t.Cleanup(func() {
+		timeNow = time.Now
+	})
+
+	ctx := context.Background()
+	key, err := keys.NewPrivateKey()
+	require.NoError(t, err)
+
+	cfg := &cache.Config{
+		Size:     10,
+		Lifetime: 24 * time.Hour,
+		Logger:   zaptest.NewLogger(t),
+	}
+
+	gateData := []*accessbox.GateData{{
+		BearerToken: &bearer.Token{},
+		GateKey:     key.PublicKey(),
+	}}
+
+	accessBox, _, err := accessbox.PackTokens(gateData, []byte("0a85c05b993e7663bdd245aa780569ee8abbdc1d9d9a9e185395ff87dffb0105"), true)
+	require.NoError(t, err)
+	data, err := accessBox.Marshal()
+	require.NoError(t, err)
+
+	var obj object.Object
+	obj.SetPayload(data)
+	var addr oid.Address
+	err = addr.DecodeString("2t6v52sJdxN2NV2bFfYnuTSQiYkbcDQ2yMKHfGSsjHiv/HbUvXKFK7meCQWoo1Es3oGSMQFbFK7Np82JVEMbCM48d")
+	require.NoError(t, err)
+
+	frostfs := newFrostFSMock()
+	frostfs.objects[getAccessKeyID(addr)] = &obj
+
+	tknCfg := tokens.Config{
+		FrostFS:     frostfs,
+		Key:         key,
+		CacheConfig: cfg,
+	}
+	creds := tokens.New(tknCfg)
+	cntr := New(creds, nil, &centerSettingsMock{})
+
+	body := bytes.NewBufferString("")
+
+	req, err := http.NewRequest("PUT", "http://localhost:8184/test/tmp.txt", body)
+	require.NoError(t, err)
+	req.Header.Set("Authorization", "AWS4-HMAC-SHA256 Credential=2t6v52sJdxN2NV2bFfYnuTSQiYkbcDQ2yMKHfGSsjHiv0HbUvXKFK7meCQWoo1Es3oGSMQFbFK7Np82JVEMbCM48d/20250310/us-east-2/s3/aws4_request, SignedHeaders=expect;host;x-amz-content-sha256;x-amz-date, Signature=966bda3d22213ae3f10d82b302041d2fc1c18804e8c02ca7d9bd35b6bcb8c161")
+	req.Header.Set("Expect", "100-continue")
+	req.Header.Set("X-Amz-Content-Sha256", UnsignedPayload)
+	req.Header.Set("X-Amz-Date", "20250310T082808Z")
+
+	_, err = cntr.Authenticate(ctx, req)
+	require.NoError(t, err)
+
+	req2, err := http.NewRequest("PUT", "http://localhost:8184/test/tmp.txt?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Credential=2t6v52sJdxN2NV2bFfYnuTSQiYkbcDQ2yMKHfGSsjHiv0HbUvXKFK7meCQWoo1Es3oGSMQFbFK7Np82JVEMbCM48d%2F20250310%2Fru%2Fs3%2Faws4_request&X-Amz-Date=20250310T083436Z&X-Amz-Expires=43200&X-Amz-SignedHeaders=expect%3Bhost&X-Amz-Signature=42c3dbe45842fdfd62d78632e135f5460e3f709ab6b949e257de30168946859b", body)
+	require.NoError(t, err)
+	req2.Header.Set("Expect", "100-continue")
+
+	_, err = cntr.Authenticate(ctx, req2)
+	require.NoError(t, err)
+}
+
 func TestCheckFormatContentSHA256(t *testing.T) {
 	defaultErr := errors.GetAPIError(errors.ErrContentSHA256Mismatch)
 
diff --git a/api/auth/signer/v4sdk2/signer/internal/v4/headers.go b/api/auth/signer/v4sdk2/signer/internal/v4/headers.go
index 46e220ce..f0e12826 100644
--- a/api/auth/signer/v4sdk2/signer/internal/v4/headers.go
+++ b/api/auth/signer/v4sdk2/signer/internal/v4/headers.go
@@ -1,6 +1,7 @@
 // This is https://github.com/aws/aws-sdk-go-v2/blob/a2b751d1ba71f59175a41f9cae5f159f1044360f/aws/signer/internal/v4/header.go
 // with changes:
 //   * drop User-Agent header from ignored
+//   * drop Expect header from ignored
 
 package v4
 
@@ -11,7 +12,7 @@ var IgnoredPresignedHeaders = Rules{
 			"Authorization":   struct{}{},
 			"User-Agent":      struct{}{},
 			"X-Amzn-Trace-Id": struct{}{},
-			"Expect":          struct{}{},
+			//"Expect":          struct{}{},
 		},
 	},
 }
@@ -24,7 +25,7 @@ var IgnoredHeaders = Rules{
 			"Authorization": struct{}{},
 			//"User-Agent":      struct{}{},
 			"X-Amzn-Trace-Id": struct{}{},
-			"Expect":          struct{}{},
+			//"Expect":          struct{}{},
 		},
 	},
 }
diff --git a/api/auth/signer/v4sdk2/signer/internal/v4/headers_test.go b/api/auth/signer/v4sdk2/signer/internal/v4/headers_test.go
index bb386599..5476a635 100644
--- a/api/auth/signer/v4sdk2/signer/internal/v4/headers_test.go
+++ b/api/auth/signer/v4sdk2/signer/internal/v4/headers_test.go
@@ -1,4 +1,6 @@
 // This is https://github.com/aws/aws-sdk-go-v2/blob/a2b751d1ba71f59175a41f9cae5f159f1044360f/aws/signer/internal/v4/header_test.go
+// with changes:
+//   * drop Expect header from ignored
 
 package v4
 
@@ -41,10 +43,10 @@ func TestIgnoredHeaders(t *testing.T) {
 		Header        string
 		ExpectIgnored bool
 	}{
-		"expect": {
-			Header:        "Expect",
-			ExpectIgnored: true,
-		},
+		//"expect": {
+		//	Header:        "Expect",
+		//	ExpectIgnored: true,
+		//},
 		"authorization": {
 			Header:        "Authorization",
 			ExpectIgnored: true,