diff --git a/lib/Auth/Process/ComputeLoA.php b/lib/Auth/Process/ComputeLoA.php
index 1b1116474c278e7dc67d8c58c65375bab377ae4a..c1f542a0f213c6bbcf037a684037c20c77bab274 100644
--- a/lib/Auth/Process/ComputeLoA.php
+++ b/lib/Auth/Process/ComputeLoA.php
@@ -40,7 +40,7 @@ class ComputeLoA extends \SimpleSAML\Auth\ProcessingFilter
     {
         parent::__construct($config, $reserved);
 
-        if (isset($config['attrName'])) {
+        if (!empty($config['attrName'])) {
             $this->attrName = $config['attrName'];
         } else {
             $this->attrName = self::DEFAULT_ATTR_NAME;
@@ -51,13 +51,13 @@ class ComputeLoA extends \SimpleSAML\Auth\ProcessingFilter
     {
         assert('is_array($request)');
 
-        if (isset($request['Attributes'][$this->attrName])) {
+        if (!empty($request['Attributes'][$this->attrName])) {
             return;
         }
         $this->metadata = MetaDataStorageHandler::getMetadataHandler();
         $sourceIdpMeta = $this->metadata->getMetaData($request['saml:sp:IdP'], 'saml20-idp-remote');
 
-        if (isset($sourceIdpMeta['EntityAttributes']['http://macedir.org/entity-category'])) {
+        if (!empty($sourceIdpMeta['EntityAttributes']['http://macedir.org/entity-category'])) {
             $entityCategoryAttributes = $sourceIdpMeta['EntityAttributes']['http://macedir.org/entity-category'];
         } else {
             Logger::error('cesnet:ComputeLoA - There are no element with name \'EntityAttributes\' '
@@ -66,7 +66,7 @@ class ComputeLoA extends \SimpleSAML\Auth\ProcessingFilter
             $entityCategoryAttributes = [];
         }
 
-        if (isset($request['Attributes']['eduPersonScopedAffiliation'])) {
+        if (!empty($request['Attributes']['eduPersonScopedAffiliation'])) {
             $this->eduPersonScopedAffiliation = $request['Attributes']['eduPersonScopedAffiliation'];
         } else {
             Logger::error(
diff --git a/lib/Auth/Process/IsCesnetEligible.php b/lib/Auth/Process/IsCesnetEligible.php
index f7d0124d943b6baf2d1bc16b1aabb75fb54b7017..b2ab6f028691708cbed70a3ef4e3db8b56bf9a95 100644
--- a/lib/Auth/Process/IsCesnetEligible.php
+++ b/lib/Auth/Process/IsCesnetEligible.php
@@ -85,7 +85,7 @@ class IsCesnetEligible extends ProcessingFilter
     {
         parent::__construct($config, $reserved);
         $conf = Configuration::loadFromArray($config);
-        if (!isset($config[self::RPC_ATTRIBUTE_NAME]) || empty($config[self::RPC_ATTRIBUTE_NAME])) {
+        if (empty($config[self::RPC_ATTRIBUTE_NAME])) {
             throw new Exception(
                 'cesnet:IsCesnetEligible - missing mandatory configuration option \'' . self::RPC_ATTRIBUTE_NAME . '\'.'
             );
@@ -96,13 +96,13 @@ class IsCesnetEligible extends ProcessingFilter
         $this->cesnetLdapConnector = (new AdapterLdap(self::CONFIG_FILE_NAME))->getConnector();
         $this->rpcAdapter = Adapter::getInstance(Adapter::RPC);
 
-        if (isset($config[self::ATTR_NAME]) && !empty($config[self::ATTR_NAME])) {
+        if (!empty($config[self::ATTR_NAME])) {
             $this->returnAttrName = $config['attrName'];
         }
 
         if (
-            isset($config[self::INTERFACE_PROPNAME], $config[self::LDAP_ATTRIBUTE_NAME]) &&
-            $config[self::INTERFACE_PROPNAME] === self::LDAP && !empty($config[self::LDAP_ATTRIBUTE_NAME])
+            ($config[self::INTERFACE_PROPNAME] ?? self::RPC) === self::LDAP
+            && !empty($config[self::LDAP_ATTRIBUTE_NAME])
         ) {
             $this->interface = $config[self::INTERFACE_PROPNAME];
             $this->ldapAttrName = $config[self::LDAP_ATTRIBUTE_NAME];
@@ -119,7 +119,7 @@ class IsCesnetEligible extends ProcessingFilter
             $conf->getString(self::PERUN_USER_SPONSORING_ORGANIZATIONS_ATTR_NAME, null);
         $this->userAffiliationsAttrName = $conf->getString(self::PERUN_USER_AFFILIATIONS_ATTR_NAME, null);
 
-        if (!isset($this->userAffiliationsAttrName, $this->userSponsoringOrganizationsAttrName)) {
+        if (empty($this->userAffiliationsAttrName) || empty($this->userSponsoringOrganizationsAttrName)) {
             Logger::warning(
                 'cesnet:IsCesnetEligible - One of attributes [' . $this->userAffiliationsAttrName . ', ' .
                 $this->userSponsoringOrganizationsAttrName . '] wasn\'t set!'
@@ -129,7 +129,7 @@ class IsCesnetEligible extends ProcessingFilter
 
     public function process(&$request)
     {
-        if (isset($request['perun']['user'])) {
+        if (!empty($request['perun']['user'])) {
             $user = $request['perun']['user'];
         } else {
             Logger::debug(
@@ -140,7 +140,7 @@ class IsCesnetEligible extends ProcessingFilter
         }
         $this->idpEntityId = $request['saml:sp:IdP'];
 
-        if (isset($request['Attributes']['eduPersonScopedAffiliation'])) {
+        if (!empty($request['Attributes']['eduPersonScopedAffiliation'])) {
             $this->eduPersonScopedAffiliation
                 = $request['Attributes']['eduPersonScopedAffiliation'];
         } else {
@@ -153,7 +153,7 @@ class IsCesnetEligible extends ProcessingFilter
         if (!empty($user)) {
             if ($this->interface === self::LDAP) {
                 $attrs = $this->adapter->getUserAttributes($user, [$this->ldapAttrName]);
-                if (isset($attrs[$this->ldapAttrName][0])) {
+                if (!empty($attrs[$this->ldapAttrName][0])) {
                     $this->cesnetEligibleLastSeenValue = $attrs[$this->ldapAttrName][0];
                 }
             } else {
diff --git a/lib/Auth/Process/IsEinfraCZEligible.php b/lib/Auth/Process/IsEinfraCZEligible.php
index 8ca1cf063e7cd760ae019e6e2003cf3fad310291..342a8d7ad9ebf2879630698e5ad946f9945d7e00 100644
--- a/lib/Auth/Process/IsEinfraCZEligible.php
+++ b/lib/Auth/Process/IsEinfraCZEligible.php
@@ -61,7 +61,7 @@ class IsEinfraCZEligible extends ProcessingFilter
     public function process(&$request)
     {
         $userScopedAffiliations = [];
-        if (isset($request['Attributes'][$this->userAffiliationAttr])) {
+        if (!empty($request['Attributes'][$this->userAffiliationAttr])) {
             $userScopedAffiliations
                 = $request['Attributes'][$this->userAffiliationAttr];
         } else {