diff --git a/src/SPIDAuth.php b/src/SPIDAuth.php
index 6c5d128..a296dcd 100644
--- a/src/SPIDAuth.php
+++ b/src/SPIDAuth.php
@@ -65,7 +65,7 @@ public function doLogin(): RedirectResponse
             $idp = request('provider');
             $this->checkIdp($idp);
 
-            $relayState = $this->getRandomRelayState();
+            $relayState = $this->getRandomString();
             $idpRedirectTo = $this->getSAML($idp)->login($relayState, [], true, false, true);
             $requestDocument = new DOMDocument();
             SAMLUtils::loadXML($requestDocument, $this->getSAML($idp)->getLastRequestXML());
@@ -161,10 +161,11 @@ public function acs(): RedirectResponse
 
         $SPIDUser = new SPIDUser($attributes);
         $idpEntityName = $this->getIdpEntityName($lastResponseXML);
+        $spidSessionIndex = $this->getSAML($idp)->getSessionIndex() ?? $this->getRandomString();
 
         session(['spid_idp' => $idp]);
         session(['spid_idpEntityName' => $idpEntityName]);
-        session(['spid_sessionIndex' => $this->getSAML($idp)->getSessionIndex()]);
+        session(['spid_sessionIndex' => $spidSessionIndex]);
         session(['spid_nameId' => $this->getSAML($idp)->getNameId()]);
         session(['spid_user' => $SPIDUser]);
 
@@ -752,12 +753,12 @@ protected function getIdpEntityName(string $responseXML)
     }
 
     /**
-     * Return a random string to be used as RelayState value.
+     * Return a random string.
      *
      * @return string random string
      * @codeCoverageIgnore
      */
-    protected function getRandomRelayState(): string
+    protected function getRandomString(): string
     {
         return Str::random(32);
     }
diff --git a/tests/ResponseValidationTest.php b/tests/ResponseValidationTest.php
index d3b6bea..2826720 100644
--- a/tests/ResponseValidationTest.php
+++ b/tests/ResponseValidationTest.php
@@ -198,7 +198,7 @@ public function testWrongAuthContextClassRef()
     public function testInvalidResponseIssueInstant()
     {
         $this->runValidationTest([
-            'responseXmlFile' => 'valid.xml',
+            'responseXmlFile' => 'valid_level1.xml',
             'responseIssueInstant' => 'invalid-response-issue-instant',
             'exceptionMessage' => 'SAML response validation error: invalid IssueInstant attribute',
         ]);
@@ -207,7 +207,7 @@ public function testInvalidResponseIssueInstant()
     public function testInvalidAssertionIssueInstant()
     {
         $this->runValidationTest([
-            'responseXmlFile' => 'valid.xml',
+            'responseXmlFile' => 'valid_level1.xml',
             'assertionIssueInstant' => 'invalid-assertion-issue-instant',
             'exceptionMessage' => 'SAML response validation error: invalid IssueInstant attribute',
         ]);
@@ -216,13 +216,13 @@ public function testInvalidAssertionIssueInstant()
     public function testWrongResponseIssueInstant()
     {
         $this->runValidationTest([
-            'responseXmlFile' => 'valid.xml',
+            'responseXmlFile' => 'valid_level1.xml',
             'responseIssueInstant' => SAMLUtils::parseTime2SAML(time() + 400),
             'exceptionMessage' => 'SAML response validation error: wrong Response IssueInstant attribute',
         ]);
 
         $this->runValidationTest([
-            'responseXmlFile' => 'valid.xml',
+            'responseXmlFile' => 'valid_level1.xml',
             'responseIssueInstant' => SAMLUtils::parseTime2SAML(time() - 400),
             'exceptionMessage' => 'SAML response validation error: wrong Response IssueInstant attribute',
         ]);
@@ -231,13 +231,13 @@ public function testWrongResponseIssueInstant()
     public function testWrongAssertionIssueInstant()
     {
         $this->runValidationTest([
-            'responseXmlFile' => 'valid.xml',
+            'responseXmlFile' => 'valid_level1.xml',
             'assertionIssueInstant' => SAMLUtils::parseTime2SAML(time() + 400),
             'exceptionMessage' => 'SAML response validation error: wrong Assertion IssueInstant attribute',
         ]);
 
         $this->runValidationTest([
-            'responseXmlFile' => 'valid.xml',
+            'responseXmlFile' => 'valid_level1.xml',
             'assertionIssueInstant' => SAMLUtils::parseTime2SAML(time() - 400),
             'exceptionMessage' => 'SAML response validation error: wrong Assertion IssueInstant attribute',
         ]);
diff --git a/tests/SPIDAuthBaseTestCase.php b/tests/SPIDAuthBaseTestCase.php
index 5e65c60..d433cf3 100644
--- a/tests/SPIDAuthBaseTestCase.php
+++ b/tests/SPIDAuthBaseTestCase.php
@@ -47,10 +47,10 @@ protected function getPackageProviders($app)
         return ['Italia\SPIDAuth\ServiceProvider'];
     }
 
-    protected function setSPIDAuthMock()
+    protected function setSPIDAuthMock($spidLevel = 1)
     {
         $testRedirectURL = $this->app['config']->get('spid-idps.test.singleSignOnService.url');
-        $responseXML = file_get_contents(__DIR__ . '/responses/valid.xml');
+        $responseXML = file_get_contents(__DIR__ . "/responses/valid_level{$spidLevel}.xml");
         $compiledResponseXML = str_replace('{{IssueInstant}}', SAMLUtils::parseTime2SAML(time()), $responseXML);
         $compiledResponseXML = str_replace('{{ResponseIssueInstant}}', SAMLUtils::parseTime2SAML(time()), $compiledResponseXML);
         $compiledResponseXML = str_replace('{{AssertionIssueInstant}}', SAMLUtils::parseTime2SAML(time()), $compiledResponseXML);
@@ -79,7 +79,9 @@ protected function setSPIDAuthMock()
             <samlp:AuthnRequest xmlns:samlp="urn:oasis:names:tc:SAML:2.0:protocol" IssueInstant="' . SAMLUtils::parseTime2SAML(time()) . '" />'
         );
         $SAMLAuth->shouldReceive('getLastResponseXML')->andReturn($compiledResponseXML)->byDefault();
-        $SAMLAuth->shouldReceive('getSessionIndex')->andReturn('sessionIndex');
+        $SAMLAuth->shouldReceive('getSessionIndex')->andReturnUsing(function () use ($spidLevel) {
+            return $spidLevel > 1 ? null : 'sessionIndex';
+        });
         $SAMLAuth->shouldReceive('getNameId')->andReturn('nameId');
         $SAMLAuth->shouldReceive('logout')->with(URL::to($this->afterLogoutURL), [], 'nameId', 'sessionIndex', false, SAMLConstants::NAMEID_TRANSIENT, 'spid-testenv')->andReturn(
             Response::redirectTo($this->logoutURL)
@@ -150,7 +152,7 @@ protected function setSPIDAuthMock()
         });
 
         $SPIDAuth->shouldReceive('getSAML')->andReturn($SAMLAuth);
-        $SPIDAuth->shouldReceive('getRandomRelayState')->andReturn('RANDOM_STRING');
+        $SPIDAuth->shouldReceive('getRandomString')->andReturn('RANDOM_STRING');
         $this->app->instance('SPIDAuth', $SPIDAuth);
 
         return $SAMLAuth;
diff --git a/tests/SPIDAuthTest.php b/tests/SPIDAuthTest.php
index abb08f7..9a1a1e2 100644
--- a/tests/SPIDAuthTest.php
+++ b/tests/SPIDAuthTest.php
@@ -114,10 +114,11 @@ public function testDoLogin()
         $response->assertRedirect();
     }
 
-    public function testAcs()
+    public function testAcs($spidLevel = 1)
     {
         Event::fake();
-        $this->setSPIDAuthMock();
+        $this->setSPIDAuthMock($spidLevel);
+        $expectedSessionIndex = $spidLevel > 1 ? 'RANDOM_STRING' : 'sessionIndex';
 
         $response = $this->withCookies([
             'spid_lastRequestId' => 'UNIQUE_ID',
@@ -126,7 +127,7 @@ public function testAcs()
         ])->post($this->acsURL);
 
         $response->assertSessionHas('spid_idpEntityName', 'Test IdP');
-        $response->assertSessionHas('spid_sessionIndex', 'sessionIndex');
+        $response->assertSessionHas('spid_sessionIndex', $expectedSessionIndex);
         $response->assertSessionHas('spid_nameId', 'nameId');
         $response->assertSessionHas('spid_user');
         $response->assertRedirect($this->afterLoginURL);
@@ -259,6 +260,16 @@ public function testAcsWithReplayAttack()
         $response->assertStatus(500);
     }
 
+    public function testAcsWithSpidLevel2()
+    {
+        $this->testAcs(2);
+    }
+
+    public function testAcsWithSpidLevel3()
+    {
+        $this->testAcs(3);
+    }
+
     public function testLogout()
     {
         $this->testAcs();
diff --git a/tests/responses/empty_audiencerestriction.xml b/tests/responses/empty_audiencerestriction.xml
index 4b51b81..d29a0c7 100644
--- a/tests/responses/empty_audiencerestriction.xml
+++ b/tests/responses/empty_audiencerestriction.xml
@@ -34,7 +34,7 @@
         </saml:Conditions>
         <saml:AuthnStatement
             AuthnInstant="{{AuthnIstant}}"
-            SessionIndex="{{SessionIndex}}">
+            SessionIndex="sessionIndex">
             <saml:AuthnContext>
                 <saml:AuthnContextClassRef>https://www.spid.gov.it/SpidL1</saml:AuthnContextClassRef>
             </saml:AuthnContext>
diff --git a/tests/responses/empty_conditions.xml b/tests/responses/empty_conditions.xml
index 882ac57..7efa176 100644
--- a/tests/responses/empty_conditions.xml
+++ b/tests/responses/empty_conditions.xml
@@ -30,7 +30,7 @@
             NotOnOrAfter="{{NotOnOrAfter}}" />
         <saml:AuthnStatement
             AuthnInstant="{{AuthnIstant}}"
-            SessionIndex="{{SessionIndex}}">
+            SessionIndex="sessionIndex">
             <saml:AuthnContext>
                 <saml:AuthnContextClassRef>https://www.spid.gov.it/SpidL1</saml:AuthnContextClassRef>
             </saml:AuthnContext>
diff --git a/tests/responses/empty_conditions_notbefore.xml b/tests/responses/empty_conditions_notbefore.xml
index 768df81..c38c1de 100644
--- a/tests/responses/empty_conditions_notbefore.xml
+++ b/tests/responses/empty_conditions_notbefore.xml
@@ -33,7 +33,7 @@
         </saml:Conditions>
         <saml:AuthnStatement
             AuthnInstant="{{AuthnIstant}}"
-            SessionIndex="{{SessionIndex}}">
+            SessionIndex="sessionIndex">
             <saml:AuthnContext>
                 <saml:AuthnContextClassRef>https://www.spid.gov.it/SpidL1</saml:AuthnContextClassRef>
             </saml:AuthnContext>
diff --git a/tests/responses/empty_conditions_notonorafter.xml b/tests/responses/empty_conditions_notonorafter.xml
index 5416127..3c9d3c9 100644
--- a/tests/responses/empty_conditions_notonorafter.xml
+++ b/tests/responses/empty_conditions_notonorafter.xml
@@ -33,7 +33,7 @@
         </saml:Conditions>
         <saml:AuthnStatement
             AuthnInstant="{{AuthnIstant}}"
-            SessionIndex="{{SessionIndex}}">
+            SessionIndex="sessionIndex">
             <saml:AuthnContext>
                 <saml:AuthnContextClassRef>https://www.spid.gov.it/SpidL1</saml:AuthnContextClassRef>
             </saml:AuthnContext>
diff --git a/tests/responses/empty_nameid.xml b/tests/responses/empty_nameid.xml
index 0dd47d4..6c97b06 100644
--- a/tests/responses/empty_nameid.xml
+++ b/tests/responses/empty_nameid.xml
@@ -33,7 +33,7 @@
         </saml:Conditions>
         <saml:AuthnStatement
             AuthnInstant="{{AuthnIstant}}"
-            SessionIndex="{{SessionIndex}}">
+            SessionIndex="sessionIndex">
             <saml:AuthnContext>
                 <saml:AuthnContextClassRef>https://www.spid.gov.it/SpidL1</saml:AuthnContextClassRef>
             </saml:AuthnContext>
diff --git a/tests/responses/empty_subjectconfirmationdata_recipient.xml b/tests/responses/empty_subjectconfirmationdata_recipient.xml
index c8844ca..1f0c847 100644
--- a/tests/responses/empty_subjectconfirmationdata_recipient.xml
+++ b/tests/responses/empty_subjectconfirmationdata_recipient.xml
@@ -34,7 +34,7 @@
         </saml:Conditions>
         <saml:AuthnStatement
             AuthnInstant="{{AuthnIstant}}"
-            SessionIndex="{{SessionIndex}}">
+            SessionIndex="sessionIndex">
             <saml:AuthnContext>
                 <saml:AuthnContextClassRef>https://www.spid.gov.it/SpidL1</saml:AuthnContextClassRef>
             </saml:AuthnContext>
diff --git a/tests/responses/missing_destination.xml b/tests/responses/missing_destination.xml
index 55c9a0e..c500d73 100644
--- a/tests/responses/missing_destination.xml
+++ b/tests/responses/missing_destination.xml
@@ -33,7 +33,7 @@
         </saml:Conditions>
         <saml:AuthnStatement
             AuthnInstant="{{AuthnIstant}}"
-            SessionIndex="{{SessionIndex}}">
+            SessionIndex="sessionIndex">
             <saml:AuthnContext>
                 <saml:AuthnContextClassRef>https://www.spid.gov.it/SpidL1</saml:AuthnContextClassRef>
             </saml:AuthnContext>
diff --git a/tests/responses/missing_inresponseto.xml b/tests/responses/missing_inresponseto.xml
index 844d250..45cd035 100644
--- a/tests/responses/missing_inresponseto.xml
+++ b/tests/responses/missing_inresponseto.xml
@@ -33,7 +33,7 @@
         </saml:Conditions>
         <saml:AuthnStatement
             AuthnInstant="{{AuthnIstant}}"
-            SessionIndex="{{SessionIndex}}">
+            SessionIndex="sessionIndex">
             <saml:AuthnContext>
                 <saml:AuthnContextClassRef>https://www.spid.gov.it/SpidL1</saml:AuthnContextClassRef>
             </saml:AuthnContext>
diff --git a/tests/responses/missing_nameid_namequalifier.xml b/tests/responses/missing_nameid_namequalifier.xml
index a5a79e4..4ea66e9 100644
--- a/tests/responses/missing_nameid_namequalifier.xml
+++ b/tests/responses/missing_nameid_namequalifier.xml
@@ -33,7 +33,7 @@
         </saml:Conditions>
         <saml:AuthnStatement
             AuthnInstant="{{AuthnIstant}}"
-            SessionIndex="{{SessionIndex}}">
+            SessionIndex="sessionIndex">
             <saml:AuthnContext>
                 <saml:AuthnContextClassRef>https://www.spid.gov.it/SpidL1</saml:AuthnContextClassRef>
             </saml:AuthnContext>
diff --git a/tests/responses/missing_subjectconfirmationdata_inresponseto.xml b/tests/responses/missing_subjectconfirmationdata_inresponseto.xml
index 4367915..a99ba5a 100644
--- a/tests/responses/missing_subjectconfirmationdata_inresponseto.xml
+++ b/tests/responses/missing_subjectconfirmationdata_inresponseto.xml
@@ -33,7 +33,7 @@
         </saml:Conditions>
         <saml:AuthnStatement
             AuthnInstant="{{AuthnIstant}}"
-            SessionIndex="{{SessionIndex}}">
+            SessionIndex="sessionIndex">
             <saml:AuthnContext>
                 <saml:AuthnContextClassRef>https://www.spid.gov.it/SpidL1</saml:AuthnContextClassRef>
             </saml:AuthnContext>
diff --git a/tests/responses/valid.xml b/tests/responses/valid_level1.xml
similarity index 97%
rename from tests/responses/valid.xml
rename to tests/responses/valid_level1.xml
index 78a5f4b..ac6d85c 100644
--- a/tests/responses/valid.xml
+++ b/tests/responses/valid_level1.xml
@@ -34,7 +34,7 @@
         </saml:Conditions>
         <saml:AuthnStatement
             AuthnInstant="{{AuthnIstant}}"
-            SessionIndex="{{SessionIndex}}">
+            SessionIndex="sessionIndex">
             <saml:AuthnContext>
                 <saml:AuthnContextClassRef>https://www.spid.gov.it/SpidL1</saml:AuthnContextClassRef>
             </saml:AuthnContext>
diff --git a/tests/responses/valid_level2.xml b/tests/responses/valid_level2.xml
new file mode 100644
index 0000000..c48f620
--- /dev/null
+++ b/tests/responses/valid_level2.xml
@@ -0,0 +1,45 @@
+<samlp:Response
+    Destination="{{AssertionConsumerURL}}"
+    ID="{{ResponseID}}"
+    InResponseTo="{{AuthnRequestID}}"
+    IssueInstant="{{ResponseIssueInstant}}"
+    Version="2.0" xmlns:saml="urn:oasis:names:tc:SAML:2.0:assertion"
+    xmlns:samlp="urn:oasis:names:tc:SAML:2.0:protocol">
+    <saml:Issuer Format="urn:oasis:names:tc:SAML:2.0:nameid-format:entity">spid-testenv</saml:Issuer>
+
+    <samlp:Status><samlp:StatusCode Value="urn:oasis:names:tc:SAML:2.0:status:Success"/></samlp:Status>
+    <saml:Assertion ID="{{AssertionID}}" IssueInstant="{{AssertionIssueInstant}}"
+        Version="2.0" xmlns:xs="http://www.w3.org/2001/XMLSchema"
+        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+        <saml:Issuer Format="urn:oasis:names:tc:SAML:2.0:nameid-format:entity">spid-testenv</saml:Issuer>
+        <saml:Subject>
+            <saml:NameID
+                Format="urn:oasis:names:tc:SAML:2.0:nameid-format:transient"
+                NameQualifier="{{NameIDNameQualifier}}">
+                    {{NameID}}
+            </saml:NameID>
+            <saml:SubjectConfirmation Method="urn:oasis:names:tc:SAML:2.0:cm:bearer">
+                <saml:SubjectConfirmationData
+                    InResponseTo="{{AuthnRequestID}}"
+                    NotOnOrAfter="{{NotOnOrAfter}}"
+                    Recipient="{{AssertionConsumerURL}}" />
+            </saml:SubjectConfirmation>
+        </saml:Subject>
+        <saml:Conditions
+            NotBefore="{{IssueInstant}}"
+            NotOnOrAfter="{{NotOnOrAfter}}">
+            <saml:AudienceRestriction>
+                <saml:Audience>{{Audience}}</saml:Audience>
+            </saml:AudienceRestriction>
+        </saml:Conditions>
+        <saml:AuthnStatement
+            AuthnInstant="{{AuthnIstant}}">
+            <saml:AuthnContext>
+                <saml:AuthnContextClassRef>https://www.spid.gov.it/SpidL2</saml:AuthnContextClassRef>
+            </saml:AuthnContext>
+        </saml:AuthnStatement>
+        <saml:AttributeStatement>
+            {{Attributes}}
+        </saml:AttributeStatement>
+    </saml:Assertion>
+</samlp:Response>
diff --git a/tests/responses/valid_level3.xml b/tests/responses/valid_level3.xml
new file mode 100644
index 0000000..942ba04
--- /dev/null
+++ b/tests/responses/valid_level3.xml
@@ -0,0 +1,45 @@
+<samlp:Response
+    Destination="{{AssertionConsumerURL}}"
+    ID="{{ResponseID}}"
+    InResponseTo="{{AuthnRequestID}}"
+    IssueInstant="{{ResponseIssueInstant}}"
+    Version="2.0" xmlns:saml="urn:oasis:names:tc:SAML:2.0:assertion"
+    xmlns:samlp="urn:oasis:names:tc:SAML:2.0:protocol">
+    <saml:Issuer Format="urn:oasis:names:tc:SAML:2.0:nameid-format:entity">spid-testenv</saml:Issuer>
+
+    <samlp:Status><samlp:StatusCode Value="urn:oasis:names:tc:SAML:2.0:status:Success"/></samlp:Status>
+    <saml:Assertion ID="{{AssertionID}}" IssueInstant="{{AssertionIssueInstant}}"
+        Version="2.0" xmlns:xs="http://www.w3.org/2001/XMLSchema"
+        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+        <saml:Issuer Format="urn:oasis:names:tc:SAML:2.0:nameid-format:entity">spid-testenv</saml:Issuer>
+        <saml:Subject>
+            <saml:NameID
+                Format="urn:oasis:names:tc:SAML:2.0:nameid-format:transient"
+                NameQualifier="{{NameIDNameQualifier}}">
+                    {{NameID}}
+            </saml:NameID>
+            <saml:SubjectConfirmation Method="urn:oasis:names:tc:SAML:2.0:cm:bearer">
+                <saml:SubjectConfirmationData
+                    InResponseTo="{{AuthnRequestID}}"
+                    NotOnOrAfter="{{NotOnOrAfter}}"
+                    Recipient="{{AssertionConsumerURL}}" />
+            </saml:SubjectConfirmation>
+        </saml:Subject>
+        <saml:Conditions
+            NotBefore="{{IssueInstant}}"
+            NotOnOrAfter="{{NotOnOrAfter}}">
+            <saml:AudienceRestriction>
+                <saml:Audience>{{Audience}}</saml:Audience>
+            </saml:AudienceRestriction>
+        </saml:Conditions>
+        <saml:AuthnStatement
+            AuthnInstant="{{AuthnIstant}}">
+            <saml:AuthnContext>
+                <saml:AuthnContextClassRef>https://www.spid.gov.it/SpidL3</saml:AuthnContextClassRef>
+            </saml:AuthnContext>
+        </saml:AuthnStatement>
+        <saml:AttributeStatement>
+            {{Attributes}}
+        </saml:AttributeStatement>
+    </saml:Assertion>
+</samlp:Response>
diff --git a/tests/responses/wrong_assertion_issuer_format.xml b/tests/responses/wrong_assertion_issuer_format.xml
index d05d33b..51a345e 100644
--- a/tests/responses/wrong_assertion_issuer_format.xml
+++ b/tests/responses/wrong_assertion_issuer_format.xml
@@ -34,7 +34,7 @@
         </saml:Conditions>
         <saml:AuthnStatement
             AuthnInstant="{{AuthnIstant}}"
-            SessionIndex="{{SessionIndex}}">
+            SessionIndex="sessionIndex">
             <saml:AuthnContext>
                 <saml:AuthnContextClassRef>https://www.spid.gov.it/SpidL1</saml:AuthnContextClassRef>
             </saml:AuthnContext>
diff --git a/tests/responses/wrong_assertion_version.xml b/tests/responses/wrong_assertion_version.xml
index c75d519..bafa97b 100644
--- a/tests/responses/wrong_assertion_version.xml
+++ b/tests/responses/wrong_assertion_version.xml
@@ -34,7 +34,7 @@
         </saml:Conditions>
         <saml:AuthnStatement
             AuthnInstant="{{AuthnIstant}}"
-            SessionIndex="{{SessionIndex}}">
+            SessionIndex="sessionIndex">
             <saml:AuthnContext>
                 <saml:AuthnContextClassRef>https://www.spid.gov.it/SpidL1</saml:AuthnContextClassRef>
             </saml:AuthnContext>
diff --git a/tests/responses/wrong_authcontextclassref.xml b/tests/responses/wrong_authcontextclassref.xml
index 886617f..f813376 100644
--- a/tests/responses/wrong_authcontextclassref.xml
+++ b/tests/responses/wrong_authcontextclassref.xml
@@ -34,7 +34,7 @@
         </saml:Conditions>
         <saml:AuthnStatement
             AuthnInstant="{{AuthnIstant}}"
-            SessionIndex="{{SessionIndex}}">
+            SessionIndex="sessionIndex">
             <saml:AuthnContext>
                 <saml:AuthnContextClassRef>urn:oasis:names:tc:SAML:2.0:ac:classes:SpidL1</saml:AuthnContextClassRef>
             </saml:AuthnContext>
diff --git a/tests/responses/wrong_issuer_format.xml b/tests/responses/wrong_issuer_format.xml
index 94621a2..fec6704 100644
--- a/tests/responses/wrong_issuer_format.xml
+++ b/tests/responses/wrong_issuer_format.xml
@@ -34,7 +34,7 @@
         </saml:Conditions>
         <saml:AuthnStatement
             AuthnInstant="{{AuthnIstant}}"
-            SessionIndex="{{SessionIndex}}">
+            SessionIndex="sessionIndex">
             <saml:AuthnContext>
                 <saml:AuthnContextClassRef>https://www.spid.gov.it/SpidL1</saml:AuthnContextClassRef>
             </saml:AuthnContext>
diff --git a/tests/responses/wrong_nameid_format.xml b/tests/responses/wrong_nameid_format.xml
index 4c875db..888df08 100644
--- a/tests/responses/wrong_nameid_format.xml
+++ b/tests/responses/wrong_nameid_format.xml
@@ -34,7 +34,7 @@
         </saml:Conditions>
         <saml:AuthnStatement
             AuthnInstant="{{AuthnIstant}}"
-            SessionIndex="{{SessionIndex}}">
+            SessionIndex="sessionIndex">
             <saml:AuthnContext>
                 <saml:AuthnContextClassRef>https://www.spid.gov.it/SpidL1</saml:AuthnContextClassRef>
             </saml:AuthnContext>