diff --git a/composer.json b/composer.json
index 270c2d5..2306a46 100644
--- a/composer.json
+++ b/composer.json
@@ -39,7 +39,8 @@
     },
     "config": {
         "allow-plugins": {
-            "composer/package-versions-deprecated": true
+            "composer/package-versions-deprecated": true,
+            "dealerdirect/phpcodesniffer-composer-installer": true
         }
     }
 }
diff --git a/src/SOAP11/XML/env/AbstractSoapElement.php b/src/SOAP11/XML/env/AbstractSoapElement.php
index 183843c..b8eb3f0 100644
--- a/src/SOAP11/XML/env/AbstractSoapElement.php
+++ b/src/SOAP11/XML/env/AbstractSoapElement.php
@@ -4,8 +4,8 @@
 
 namespace SimpleSAML\SOAP11\XML\env;
 
-use SimpleSAML\XML\AbstractElement;
 use SimpleSAML\SOAP\Constants as C;
+use SimpleSAML\XML\AbstractElement;
 
 /**
  * Abstract class to be implemented by all the classes in this namespace
diff --git a/src/SOAP11/XML/env/Body.php b/src/SOAP11/XML/env/Body.php
index 899effb..f9012c4 100644
--- a/src/SOAP11/XML/env/Body.php
+++ b/src/SOAP11/XML/env/Body.php
@@ -10,8 +10,8 @@
 use SimpleSAML\SOAP\Exception\ProtocolViolationException;
 use SimpleSAML\XML\Chunk;
 use SimpleSAML\XML\Exception\InvalidDOMElementException;
-use SimpleSAML\XML\ExtendableElementTrait;
 use SimpleSAML\XML\ExtendableAttributesTrait;
+use SimpleSAML\XML\ExtendableElementTrait;
 use SimpleSAML\XML\XsNamespace as NS;
 
 use function array_diff;
diff --git a/src/SOAP11/XML/env/Envelope.php b/src/SOAP11/XML/env/Envelope.php
index e97c9a7..7c7e279 100644
--- a/src/SOAP11/XML/env/Envelope.php
+++ b/src/SOAP11/XML/env/Envelope.php
@@ -11,8 +11,8 @@
 use SimpleSAML\XML\Exception\InvalidDOMElementException;
 use SimpleSAML\XML\Exception\MissingElementException;
 use SimpleSAML\XML\Exception\TooManyElementsException;
-use SimpleSAML\XML\ExtendableElementTrait;
 use SimpleSAML\XML\ExtendableAttributesTrait;
+use SimpleSAML\XML\ExtendableElementTrait;
 use SimpleSAML\XML\XsNamespace as NS;
 
 /**
diff --git a/src/SOAP12/XML/env/AbstractSoapElement.php b/src/SOAP12/XML/env/AbstractSoapElement.php
index c0a2dba..1354f0d 100644
--- a/src/SOAP12/XML/env/AbstractSoapElement.php
+++ b/src/SOAP12/XML/env/AbstractSoapElement.php
@@ -4,8 +4,8 @@
 
 namespace SimpleSAML\SOAP12\XML\env;
 
-use SimpleSAML\XML\AbstractElement;
 use SimpleSAML\SOAP\Constants as C;
+use SimpleSAML\XML\AbstractElement;
 
 /**
  * Abstract class to be implemented by all the classes in this namespace
diff --git a/src/SOAP12/XML/env/Node.php b/src/SOAP12/XML/env/Node.php
index 240f383..83f6ee8 100644
--- a/src/SOAP12/XML/env/Node.php
+++ b/src/SOAP12/XML/env/Node.php
@@ -5,8 +5,8 @@
 namespace SimpleSAML\SOAP12\XML\env;
 
 use SimpleSAML\Assert\Assert;
-use SimpleSAML\XML\StringElementTrait;
 use SimpleSAML\XML\Exception\SchemaViolationException;
+use SimpleSAML\XML\StringElementTrait;
 
 /**
  * Class representing a env:Node element.
diff --git a/src/SOAP12/XML/env/Role.php b/src/SOAP12/XML/env/Role.php
index 2fc917a..76be159 100644
--- a/src/SOAP12/XML/env/Role.php
+++ b/src/SOAP12/XML/env/Role.php
@@ -5,8 +5,8 @@
 namespace SimpleSAML\SOAP12\XML\env;
 
 use SimpleSAML\Assert\Assert;
-use SimpleSAML\XML\StringElementTrait;
 use SimpleSAML\XML\Exception\SchemaViolationException;
+use SimpleSAML\XML\StringElementTrait;
 
 /**
  * Class representing a env:Role element.
diff --git a/src/SOAP12/XML/env/Subcode.php b/src/SOAP12/XML/env/Subcode.php
index e57cece..bf5e50c 100644
--- a/src/SOAP12/XML/env/Subcode.php
+++ b/src/SOAP12/XML/env/Subcode.php
@@ -6,7 +6,6 @@
 
 use DOMElement;
 use SimpleSAML\Assert\Assert;
-use SimpleSAML\SOAP\Exception\ProtocolViolationException;
 use SimpleSAML\XML\Exception\InvalidDOMElementException;
 use SimpleSAML\XML\Exception\MissingElementException;
 use SimpleSAML\XML\Exception\TooManyElementsException;
diff --git a/src/SOAP12/XML/env/Text.php b/src/SOAP12/XML/env/Text.php
index c9b0f5b..50fb2eb 100644
--- a/src/SOAP12/XML/env/Text.php
+++ b/src/SOAP12/XML/env/Text.php
@@ -4,11 +4,7 @@
 
 namespace SimpleSAML\SOAP12\XML\env;
 
-use DOMAttr;
-use DOMElement;
-use DOMNameSpaceNode;
 use SimpleSAML\Assert\Assert;
-use SimpleSAML\XML\Exception\InvalidDOMElementException;
 use SimpleSAML\XML\LocalizedStringElementTrait;
 
 /**
diff --git a/src/SOAP12/XML/env/Value.php b/src/SOAP12/XML/env/Value.php
index 3a675b8..8cbdba4 100644
--- a/src/SOAP12/XML/env/Value.php
+++ b/src/SOAP12/XML/env/Value.php
@@ -4,7 +4,6 @@
 
 namespace SimpleSAML\SOAP12\XML\env;
 
-use SimpleSAML\Assert\Assert;
 use SimpleSAML\XML\QNameElementTrait;
 
 /**
diff --git a/tests/SOAP11/XML/env/BodyTest.php b/tests/SOAP11/XML/env/BodyTest.php
index 67c6d5b..468a7af 100644
--- a/tests/SOAP11/XML/env/BodyTest.php
+++ b/tests/SOAP11/XML/env/BodyTest.php
@@ -4,7 +4,6 @@
 
 namespace SimpleSAML\Test\SOAP11\XML\env;
 
-use DOMDocument;
 use DOMElement;
 use PHPUnit\Framework\TestCase;
 use SimpleSAML\SOAP\Exception\ProtocolViolationException;
diff --git a/tests/SOAP11/XML/env/DetailTest.php b/tests/SOAP11/XML/env/DetailTest.php
index a88b9ff..87779ff 100644
--- a/tests/SOAP11/XML/env/DetailTest.php
+++ b/tests/SOAP11/XML/env/DetailTest.php
@@ -4,7 +4,6 @@
 
 namespace SimpleSAML\Test\SOAP11\XML\env;
 
-use DOMDocument;
 use DOMElement;
 use PHPUnit\Framework\TestCase;
 use SimpleSAML\SOAP11\XML\env\Detail;
diff --git a/tests/SOAP11/XML/env/EnvelopeTest.php b/tests/SOAP11/XML/env/EnvelopeTest.php
index d0049d4..aa6d8d6 100644
--- a/tests/SOAP11/XML/env/EnvelopeTest.php
+++ b/tests/SOAP11/XML/env/EnvelopeTest.php
@@ -4,7 +4,6 @@
 
 namespace SimpleSAML\Test\SOAP11\XML\env;
 
-use DOMDocument;
 use DOMElement;
 use PHPUnit\Framework\TestCase;
 use SimpleSAML\SOAP11\XML\env\Body;
diff --git a/tests/SOAP11/XML/env/FaultCodeTest.php b/tests/SOAP11/XML/env/FaultCodeTest.php
index 99d32fa..a04fdbd 100644
--- a/tests/SOAP11/XML/env/FaultCodeTest.php
+++ b/tests/SOAP11/XML/env/FaultCodeTest.php
@@ -4,7 +4,6 @@
 
 namespace SimpleSAML\Test\SOAP11\XML\env;
 
-use DOMDocument;
 use PHPUnit\Framework\TestCase;
 use SimpleSAML\SOAP11\XML\env\FaultCode;
 use SimpleSAML\XML\DOMDocumentFactory;
diff --git a/tests/SOAP11/XML/env/FaultStringTest.php b/tests/SOAP11/XML/env/FaultStringTest.php
index b07bd53..6074825 100644
--- a/tests/SOAP11/XML/env/FaultStringTest.php
+++ b/tests/SOAP11/XML/env/FaultStringTest.php
@@ -6,7 +6,6 @@
 
 use PHPUnit\Framework\TestCase;
 use SimpleSAML\SOAP11\XML\env\FaultString;
-use SimpleSAML\SOAP11\XML\env\Text;
 use SimpleSAML\XML\DOMDocumentFactory;
 use SimpleSAML\XML\TestUtils\SerializableElementTestTrait;
 
diff --git a/tests/SOAP11/XML/env/FaultTest.php b/tests/SOAP11/XML/env/FaultTest.php
index 9c4e874..b9d87ad 100644
--- a/tests/SOAP11/XML/env/FaultTest.php
+++ b/tests/SOAP11/XML/env/FaultTest.php
@@ -4,9 +4,7 @@
 
 namespace SimpleSAML\Test\SOAP11\XML\env;
 
-use DOMDocument;
 use PHPUnit\Framework\TestCase;
-use SimpleSAML\SOAP\Constants as C;
 use SimpleSAML\SOAP11\XML\env\Detail;
 use SimpleSAML\SOAP11\XML\env\Fault;
 use SimpleSAML\SOAP11\XML\env\FaultActor;
diff --git a/tests/SOAP11/XML/env/HeaderTest.php b/tests/SOAP11/XML/env/HeaderTest.php
index c202837..a6bba73 100644
--- a/tests/SOAP11/XML/env/HeaderTest.php
+++ b/tests/SOAP11/XML/env/HeaderTest.php
@@ -4,7 +4,6 @@
 
 namespace SimpleSAML\Test\SOAP11\XML\env;
 
-use DOMDocument;
 use DOMElement;
 use PHPUnit\Framework\TestCase;
 use SimpleSAML\SOAP11\XML\env\Header;
diff --git a/tests/SOAP12/XML/env/BodyTest.php b/tests/SOAP12/XML/env/BodyTest.php
index 23da40d..ced4faf 100644
--- a/tests/SOAP12/XML/env/BodyTest.php
+++ b/tests/SOAP12/XML/env/BodyTest.php
@@ -4,7 +4,6 @@
 
 namespace SimpleSAML\Test\SOAP12\XML\env;
 
-use DOMDocument;
 use DOMElement;
 use PHPUnit\Framework\TestCase;
 use SimpleSAML\SOAP\Exception\ProtocolViolationException;
diff --git a/tests/SOAP12/XML/env/CodeTest.php b/tests/SOAP12/XML/env/CodeTest.php
index c751b8c..5baea31 100644
--- a/tests/SOAP12/XML/env/CodeTest.php
+++ b/tests/SOAP12/XML/env/CodeTest.php
@@ -4,7 +4,6 @@
 
 namespace SimpleSAML\Test\SOAP12\XML\env;
 
-use DOMDocument;
 use PHPUnit\Framework\TestCase;
 use SimpleSAML\SOAP\Constants as C;
 use SimpleSAML\SOAP12\XML\env\Code;
diff --git a/tests/SOAP12/XML/env/DetailTest.php b/tests/SOAP12/XML/env/DetailTest.php
index f499ce0..b76fac0 100644
--- a/tests/SOAP12/XML/env/DetailTest.php
+++ b/tests/SOAP12/XML/env/DetailTest.php
@@ -4,7 +4,6 @@
 
 namespace SimpleSAML\Test\SOAP12\XML\env;
 
-use DOMDocument;
 use DOMElement;
 use PHPUnit\Framework\TestCase;
 use SimpleSAML\SOAP12\XML\env\Detail;
diff --git a/tests/SOAP12/XML/env/EnvelopeTest.php b/tests/SOAP12/XML/env/EnvelopeTest.php
index 86f0e11..6087d19 100644
--- a/tests/SOAP12/XML/env/EnvelopeTest.php
+++ b/tests/SOAP12/XML/env/EnvelopeTest.php
@@ -4,7 +4,6 @@
 
 namespace SimpleSAML\Test\SOAP12\XML\env;
 
-use DOMDocument;
 use DOMElement;
 use PHPUnit\Framework\TestCase;
 use SimpleSAML\SOAP12\XML\env\Body;
diff --git a/tests/SOAP12/XML/env/FaultTest.php b/tests/SOAP12/XML/env/FaultTest.php
index 0f86d98..7d02859 100644
--- a/tests/SOAP12/XML/env/FaultTest.php
+++ b/tests/SOAP12/XML/env/FaultTest.php
@@ -4,9 +4,7 @@
 
 namespace SimpleSAML\Test\SOAP12\XML\env;
 
-use DOMDocument;
 use PHPUnit\Framework\TestCase;
-use SimpleSAML\SOAP\Constants as C;
 use SimpleSAML\SOAP12\XML\env\Code;
 use SimpleSAML\SOAP12\XML\env\Detail;
 use SimpleSAML\SOAP12\XML\env\Fault;
diff --git a/tests/SOAP12/XML/env/HeaderTest.php b/tests/SOAP12/XML/env/HeaderTest.php
index 69d8551..04e148e 100644
--- a/tests/SOAP12/XML/env/HeaderTest.php
+++ b/tests/SOAP12/XML/env/HeaderTest.php
@@ -4,7 +4,6 @@
 
 namespace SimpleSAML\Test\SOAP12\XML\env;
 
-use DOMDocument;
 use DOMElement;
 use PHPUnit\Framework\TestCase;
 use SimpleSAML\SOAP12\XML\env\Header;
diff --git a/tests/SOAP12/XML/env/SubcodeTest.php b/tests/SOAP12/XML/env/SubcodeTest.php
index f4a2e0d..aad6aad 100644
--- a/tests/SOAP12/XML/env/SubcodeTest.php
+++ b/tests/SOAP12/XML/env/SubcodeTest.php
@@ -4,7 +4,6 @@
 
 namespace SimpleSAML\Test\SOAP12\XML\env;
 
-use DOMDocument;
 use PHPUnit\Framework\TestCase;
 use SimpleSAML\SOAP12\XML\env\Subcode;
 use SimpleSAML\SOAP12\XML\env\Value;
diff --git a/tests/SOAP12/XML/env/SupportedEnvelopeTest.php b/tests/SOAP12/XML/env/SupportedEnvelopeTest.php
index 866ed99..c02a9f1 100644
--- a/tests/SOAP12/XML/env/SupportedEnvelopeTest.php
+++ b/tests/SOAP12/XML/env/SupportedEnvelopeTest.php
@@ -4,7 +4,6 @@
 
 namespace SimpleSAML\Test\SOAP12\XML\env;
 
-use DOMDocument;
 use PHPUnit\Framework\TestCase;
 use SimpleSAML\SOAP12\XML\env\SupportedEnvelope;
 use SimpleSAML\XML\DOMDocumentFactory;
diff --git a/tests/SOAP12/XML/env/UpgradeTest.php b/tests/SOAP12/XML/env/UpgradeTest.php
index a2cbf98..f53f795 100644
--- a/tests/SOAP12/XML/env/UpgradeTest.php
+++ b/tests/SOAP12/XML/env/UpgradeTest.php
@@ -4,7 +4,6 @@
 
 namespace SimpleSAML\Test\SOAP12\XML\env;
 
-use DOMDocument;
 use PHPUnit\Framework\TestCase;
 use SimpleSAML\SOAP12\XML\env\SupportedEnvelope;
 use SimpleSAML\SOAP12\XML\env\Upgrade;
diff --git a/tests/SOAP12/XML/env/ValueTest.php b/tests/SOAP12/XML/env/ValueTest.php
index 6369243..54df58c 100644
--- a/tests/SOAP12/XML/env/ValueTest.php
+++ b/tests/SOAP12/XML/env/ValueTest.php
@@ -4,7 +4,6 @@
 
 namespace SimpleSAML\Test\SOAP12\XML\env;
 
-use DOMDocument;
 use PHPUnit\Framework\TestCase;
 use SimpleSAML\SOAP12\XML\env\Value;
 use SimpleSAML\XML\DOMDocumentFactory;