diff --git a/src/XML/fed/AbstractSecurityTokenType.php b/src/XML/fed/AbstractSecurityTokenType.php
new file mode 100644
index 00000000..ed826b24
--- /dev/null
+++ b/src/XML/fed/AbstractSecurityTokenType.php
@@ -0,0 +1,107 @@
+<?php
+
+declare(strict_types=1);
+
+namespace SimpleSAML\WSSecurity\XML\fed;
+
+use DOMElement;
+use SimpleSAML\Assert\Assert;
+use SimpleSAML\XML\Chunk;
+use SimpleSAML\XML\ExtendableAttributesTrait;
+use SimpleSAML\XML\ExtendableElementTrait;
+use SimpleSAML\XML\Exception\InvalidDOMElementException;
+use SimpleSAML\XML\Exception\SchemaViolationException;
+use SimpleSAML\XML\SerializableElementInterface;
+use SimpleSAML\XML\XsNamespace as NS;
+
+/**
+ * Class defining the SecurityTokenType element
+ *
+ * @package tvdijen/ws-security
+ */
+abstract class AbstractSecurityTokenType extends AbstractFedElement
+{
+    use ExtendableAttributesTrait;
+    use ExtendableElementTrait;
+
+    /** The namespace-attribute for the xs:anyAttribute element */
+    public const XS_ANY_ATTR_NAMESPACE = NS::OTHER;
+
+    /** The namespace-attribute for the xs:any element */
+    public const XS_ANY_ELT_NAMESPACE = NS::OTHER;
+
+
+    /**
+     * AbstractSecurityTokenType constructor
+     *
+     * @param \SimpleSAML\XML\SerializableElementInterface $child
+     * @param array $namespacedAttributes
+     */
+    final public function __construct(
+        protected SerializableElementinterface $child,
+        array $namespacedAttributes = []
+    ) {
+        $this->setElements([$child]);
+        $this->setAttributesNS($namespacedAttributes);
+    }
+
+
+    /**
+     * Create an instance of this object from its XML representation.
+     *
+     * @param \DOMElement $xml
+     * @return static
+     *
+     * @throws \SimpleSAML\XML\Exception\InvalidDOMElementException
+     *   if the qualified name of the supplied element is wrong
+     */
+    public static function fromXML(DOMElement $xml): static
+    {
+        Assert::same($xml->localName, static::getLocalName(), InvalidDOMElementException::class);
+        Assert::same($xml->namespaceURI, static::NS, InvalidDOMElementException::class);
+
+        $children = [];
+        foreach ($xml->childNodes as $child) {
+            if (!($child instanceof DOMElement)) {
+                continue;
+            } elseif ($child->namespaceURI === static::NS) {
+                continue;
+            }
+
+            $children[] = new Chunk($child);
+        }
+
+        Assert::minCount($children, 1, SchemaViolationException::class);
+        Assert::maxCount($children, 1, SchemaViolationException::class);
+
+        return new static(
+            array_pop($children),
+            self::getAttributesNSFromXML($xml),
+        );
+    }
+
+
+    /**
+     * Add this AbstractSecurityTokenType to an XML element.
+     *
+     * @param \DOMElement $parent The element we should append this username token to.
+     * @return \DOMElement
+     */
+    public function toXML(DOMElement $parent = null): DOMElement
+    {
+        $e = parent::instantiateParentElement($parent);
+
+        foreach ($this->getAttributesNS() as $attr) {
+            $attr->toXML($e);
+        }
+
+        /** @psalm-var \SimpleSAML\XML\SerializableElementInterface $child */
+        foreach ($this->getElements() as $child) {
+            if (!$child->isEmptyElement()) {
+                $child->toXML($e);
+            }
+        }
+
+        return $e;
+    }
+}
diff --git a/src/XML/fed/SecurityToken.php b/src/XML/fed/SecurityToken.php
new file mode 100644
index 00000000..26233181
--- /dev/null
+++ b/src/XML/fed/SecurityToken.php
@@ -0,0 +1,14 @@
+<?php
+
+declare(strict_types=1);
+
+namespace SimpleSAML\WSSecurity\XML\fed;
+
+/**
+ * A SecurityToken element
+ *
+ * @package tvdijen/ws-security
+ */
+final class SecurityToken extends AbstractSecurityTokenType
+{
+}
diff --git a/tests/WSSecurity/XML/fed/SecurityTokenTest.php b/tests/WSSecurity/XML/fed/SecurityTokenTest.php
new file mode 100644
index 00000000..00564d5d
--- /dev/null
+++ b/tests/WSSecurity/XML/fed/SecurityTokenTest.php
@@ -0,0 +1,70 @@
+<?php
+
+declare(strict_types=1);
+
+namespace SimpleSAML\Test\WSSecurity\XML\fed;
+
+use DOMDocument;
+use PHPUnit\Framework\TestCase;
+use SimpleSAML\WSSecurity\XML\fed\SecurityToken;
+use SimpleSAML\XML\Attribute as XMLAttribute;
+use SimpleSAML\XML\Chunk;
+use SimpleSAML\XML\DOMDocumentFactory;
+use SimpleSAML\XML\TestUtils\SchemaValidationTestTrait;
+use SimpleSAML\XML\TestUtils\SerializableElementTestTrait;
+
+use function dirname;
+use function strval;
+
+/**
+ * Tests for fed:SecurityToken.
+ *
+ * @covers \SimpleSAML\WSSecurity\XML\fed\SecurityToken
+ * @covers \SimpleSAML\WSSecurity\XML\fed\AbstractSecurityTokenType
+ * @covers \SimpleSAML\WSSecurity\XML\fed\AbstractFedElement
+ * @package tvdijen/ws-security
+ */
+final class SecurityTokenTest extends TestCase
+{
+    use SchemaValidationTestTrait;
+    use SerializableElementTestTrait;
+
+
+    /**
+     */
+    public static function setUpBeforeClass(): void
+    {
+        self::$schemaFile = dirname(__FILE__, 5) . '/resources/schemas/ws-federation.xsd';
+
+        self::$testedClass = SecurityToken::class;
+
+        self::$xmlRepresentation = DOMDocumentFactory::fromFile(
+            dirname(__FILE__, 4) . '/resources/xml/fed_SecurityToken.xml',
+        );
+    }
+
+
+    // test marshalling
+
+
+    /**
+     * Test creating a SecurityToken object from scratch.
+     */
+    public function testMarshalling(): void
+    {
+        $attr1 = new XMLAttribute('urn:x-simplesamlphp:namespace', 'ssp', 'attr1', 'testval1');
+        $child = DOMDocumentFactory::fromString(
+            '<ssp:Chunk xmlns:ssp="urn:x-simplesamlphp:namespace">SomeChunk</ssp:Chunk>',
+        );
+
+        $securityToken = new SecurityToken(
+            new Chunk($child->documentElement),
+            [$attr1],
+        );
+
+        $this->assertEquals(
+            self::$xmlRepresentation->saveXML(self::$xmlRepresentation->documentElement),
+            strval($securityToken),
+        );
+    }
+}
diff --git a/tests/resources/xml/fed_SecurityToken.xml b/tests/resources/xml/fed_SecurityToken.xml
new file mode 100644
index 00000000..574e5909
--- /dev/null
+++ b/tests/resources/xml/fed_SecurityToken.xml
@@ -0,0 +1,3 @@
+<fed:SecurityToken xmlns:fed="http://docs.oasis-open.org/wsfed/federation/200706" xmlns:ssp="urn:x-simplesamlphp:namespace" ssp:attr1="testval1">
+  <ssp:Chunk>SomeChunk</ssp:Chunk>
+</fed:SecurityToken>