diff --git a/gvm/protocols/gmp/_gmpnext.py b/gvm/protocols/gmp/_gmpnext.py
index cd92aaeef..77831ea9c 100644
--- a/gvm/protocols/gmp/_gmpnext.py
+++ b/gvm/protocols/gmp/_gmpnext.py
@@ -338,6 +338,96 @@ def get_agent_support_bundle(
             )
         )
 
+    def create_active_directory_credential(
+        self,
+        name: str,
+        *,
+        host: str,
+        bind_dn: str,
+        base_dn: str,
+        bind_password: str,
+        tls_mode: str,
+        comment: str | None = None,
+        port: int | None = None,
+        ca_certificate: str | None = None,
+    ) -> T:
+        """Create an Active Directory credential.
+
+        Requires AD integration to be enabled in gvmd.
+
+        Args:
+            name: Name of the credential.
+            host: Active Directory server hostname or IP address.
+            bind_dn: Distinguished name used to bind to the directory.
+            base_dn: Base distinguished name for directory searches.
+            bind_password: Password used to bind to the directory.
+            tls_mode: TLS mode, either "ldaps" or "starttls".
+            comment: Optional comment for the credential.
+            port: Server port (1 to 65535). Omit to use the connector default.
+            ca_certificate: Optional CA certificate in PEM format.
+        """
+        return self._send_request_and_transform_response(
+            Credentials.create_active_directory_credential(
+                name=name,
+                host=host,
+                bind_dn=bind_dn,
+                base_dn=base_dn,
+                bind_password=bind_password,
+                tls_mode=tls_mode,
+                comment=comment,
+                port=port,
+                ca_certificate=ca_certificate,
+            )
+        )
+
+    def modify_active_directory_credential(
+        self,
+        credential_id: EntityID,
+        *,
+        name: str | None = None,
+        comment: str | None = None,
+        host: str | None = None,
+        bind_dn: str | None = None,
+        base_dn: str | None = None,
+        bind_password: str | None = None,
+        tls_mode: str | None = None,
+        port: int | str | None = None,
+        ca_certificate: str | None = None,
+    ) -> T:
+        """Modify an Active Directory credential.
+
+        Requires AD integration to be enabled in gvmd. Fields set to None
+        are left unchanged.
+
+        Args:
+            credential_id: UUID of the credential to modify.
+            name: New name of the credential.
+            comment: New comment. An empty string clears the comment.
+            host: Active Directory server hostname or IP address.
+            bind_dn: Distinguished name used to bind to the directory.
+            base_dn: Base distinguished name for directory searches.
+            bind_password: Password used to bind to the directory.
+            tls_mode: TLS mode, either "ldaps" or "starttls".
+            port: Server port (1 to 65535), or an empty string to restore
+                the connector default. Nonempty strings are not accepted.
+            ca_certificate: CA certificate in PEM format. An empty string
+                clears the certificate.
+        """
+        return self._send_request_and_transform_response(
+            Credentials.modify_active_directory_credential(
+                credential_id=credential_id,
+                name=name,
+                comment=comment,
+                host=host,
+                bind_dn=bind_dn,
+                base_dn=base_dn,
+                bind_password=bind_password,
+                tls_mode=tls_mode,
+                port=port,
+                ca_certificate=ca_certificate,
+            )
+        )
+
     def create_credential_store_credential(
         self,
         name: str,
diff --git a/gvm/protocols/gmp/requests/next/__init__.py b/gvm/protocols/gmp/requests/next/__init__.py
index c9b70972b..d251ec9c6 100644
--- a/gvm/protocols/gmp/requests/next/__init__.py
+++ b/gvm/protocols/gmp/requests/next/__init__.py
@@ -13,6 +13,7 @@
 from gvm.protocols.gmp.requests.next._credentials import (
     Credentials,
     CredentialStoreCredentialType,
+    CredentialType,
 )
 from gvm.protocols.gmp.requests.next._features import (
     Features,
@@ -76,7 +77,6 @@
     CertBundAdvisories,
     Cpes,
     CredentialFormat,
-    CredentialType,
     Cves,
     DfnCertAdvisories,
     EntityType,
diff --git a/gvm/protocols/gmp/requests/next/_credentials.py b/gvm/protocols/gmp/requests/next/_credentials.py
index 6868e363d..171921616 100644
--- a/gvm/protocols/gmp/requests/next/_credentials.py
+++ b/gvm/protocols/gmp/requests/next/_credentials.py
@@ -26,7 +26,229 @@ class CredentialStoreCredentialType(Enum):
     PASSWORD_ONLY = "cs_pw"
 
 
+class CredentialType(Enum):
+    """Enum for credential types"""
+
+    CLIENT_CERTIFICATE = "cc"
+    SNMP = "snmp"
+    USERNAME_PASSWORD = "up"
+    USERNAME_SSH_KEY = "usk"
+    SMIME_CERTIFICATE = "smime"
+    PGP_ENCRYPTION_KEY = "pgp"
+    PASSWORD_ONLY = "pw"
+    ACTIVE_DIRECTORY = "ad"
+
+
 class Credentials(CredentialsV224):
+    @classmethod
+    def create_active_directory_credential(
+        cls,
+        name: str,
+        *,
+        host: str,
+        bind_dn: str,
+        base_dn: str,
+        bind_password: str,
+        tls_mode: str,
+        comment: str | None = None,
+        port: int | None = None,
+        ca_certificate: str | None = None,
+    ) -> Request:
+        """Create an Active Directory credential.
+
+        Requires AD integration to be enabled in gvmd.
+
+        Args:
+            name: Name of the credential.
+            host: Active Directory server hostname or IP address.
+            bind_dn: Distinguished name used to bind to the directory.
+            base_dn: Base distinguished name for directory searches.
+            bind_password: Password used to bind to the directory.
+            tls_mode: TLS mode, either "ldaps" or "starttls".
+            comment: Optional comment for the credential.
+            port: Server port (1 to 65535). Omit to use the connector default.
+            ca_certificate: Optional CA certificate in PEM format.
+        """
+        if not name:
+            raise RequiredArgument(
+                function=cls.create_active_directory_credential.__name__,
+                argument="name",
+            )
+
+        if not host:
+            raise RequiredArgument(
+                function=cls.create_active_directory_credential.__name__,
+                argument="host",
+            )
+
+        if not bind_dn:
+            raise RequiredArgument(
+                function=cls.create_active_directory_credential.__name__,
+                argument="bind_dn",
+            )
+
+        if not base_dn:
+            raise RequiredArgument(
+                function=cls.create_active_directory_credential.__name__,
+                argument="base_dn",
+            )
+
+        if not bind_password:
+            raise RequiredArgument(
+                function=cls.create_active_directory_credential.__name__,
+                argument="bind_password",
+            )
+
+        if not tls_mode:
+            raise RequiredArgument(
+                function=cls.create_active_directory_credential.__name__,
+                argument="tls_mode",
+            )
+
+        if tls_mode not in ("ldaps", "starttls"):
+            raise InvalidArgument(
+                function=cls.create_active_directory_credential.__name__,
+                argument="tls_mode",
+            )
+
+        if port is not None and (
+            not isinstance(port, int) or not 1 <= port <= 65535
+        ):
+            raise InvalidArgument(
+                function=cls.create_active_directory_credential.__name__,
+                argument="port",
+            )
+
+        cmd = XmlCommand("create_credential")
+        cmd.add_element("name", name)
+        cmd.add_element("type", CredentialType.ACTIVE_DIRECTORY.value)
+        if comment is not None:
+            cmd.add_element("comment", comment)
+        cmd.add_element("host", host)
+        cmd.add_element("bind_dn", bind_dn)
+        cmd.add_element("base_dn", base_dn)
+        cmd.add_element("bind_password", bind_password)
+        cmd.add_element("tls_mode", tls_mode)
+        if port is not None:
+            cmd.add_element("port", str(port))
+        if ca_certificate is not None:
+            cmd.add_element("ca_certificate", ca_certificate)
+        return cmd
+
+    @classmethod
+    def modify_active_directory_credential(
+        cls,
+        credential_id: EntityID,
+        *,
+        name: str | None = None,
+        comment: str | None = None,
+        host: str | None = None,
+        bind_dn: str | None = None,
+        base_dn: str | None = None,
+        bind_password: str | None = None,
+        tls_mode: str | None = None,
+        port: int | str | None = None,
+        ca_certificate: str | None = None,
+    ) -> Request:
+        """Modify an Active Directory credential.
+
+        Requires AD integration to be enabled in gvmd. Fields set to None
+        are left unchanged.
+
+        Args:
+            credential_id: UUID of the credential to modify.
+            name: New name of the credential.
+            comment: New comment. An empty string clears the comment.
+            host: Active Directory server hostname or IP address.
+            bind_dn: Distinguished name used to bind to the directory.
+            base_dn: Base distinguished name for directory searches.
+            bind_password: Password used to bind to the directory.
+            tls_mode: TLS mode, either "ldaps" or "starttls".
+            port: Server port (1 to 65535), or an empty string to restore
+                the connector default. Nonempty strings are not accepted.
+            ca_certificate: CA certificate in PEM format. An empty string
+                clears the certificate.
+        """
+        if not credential_id:
+            raise RequiredArgument(
+                function=cls.modify_active_directory_credential.__name__,
+                argument="credential_id",
+            )
+
+        if name is not None and not name:
+            raise RequiredArgument(
+                function=cls.modify_active_directory_credential.__name__,
+                argument="name",
+            )
+
+        if host is not None and not host:
+            raise RequiredArgument(
+                function=cls.modify_active_directory_credential.__name__,
+                argument="host",
+            )
+
+        if bind_dn is not None and not bind_dn:
+            raise RequiredArgument(
+                function=cls.modify_active_directory_credential.__name__,
+                argument="bind_dn",
+            )
+
+        if base_dn is not None and not base_dn:
+            raise RequiredArgument(
+                function=cls.modify_active_directory_credential.__name__,
+                argument="base_dn",
+            )
+
+        if bind_password is not None and not bind_password:
+            raise RequiredArgument(
+                function=cls.modify_active_directory_credential.__name__,
+                argument="bind_password",
+            )
+
+        if tls_mode is not None and not tls_mode:
+            raise RequiredArgument(
+                function=cls.modify_active_directory_credential.__name__,
+                argument="tls_mode",
+            )
+
+        if tls_mode is not None and tls_mode not in ("ldaps", "starttls"):
+            raise InvalidArgument(
+                function=cls.modify_active_directory_credential.__name__,
+                argument="tls_mode",
+            )
+
+        if (
+            port is not None
+            and port != ""
+            and (not isinstance(port, int) or not 1 <= port <= 65535)
+        ):
+            raise InvalidArgument(
+                function=cls.modify_active_directory_credential.__name__,
+                argument="port",
+            )
+
+        cmd = XmlCommand("modify_credential")
+        cmd.set_attribute("credential_id", str(credential_id))
+        if name is not None:
+            cmd.add_element("name", str(name))
+        if comment is not None:
+            cmd.add_element("comment", str(comment))
+        if host is not None:
+            cmd.add_element("host", str(host))
+        if bind_dn is not None:
+            cmd.add_element("bind_dn", str(bind_dn))
+        if base_dn is not None:
+            cmd.add_element("base_dn", str(base_dn))
+        if bind_password is not None:
+            cmd.add_element("bind_password", str(bind_password))
+        if tls_mode is not None:
+            cmd.add_element("tls_mode", str(tls_mode))
+        if port is not None:
+            cmd.add_element("port", str(port))
+        if ca_certificate is not None:
+            cmd.add_element("ca_certificate", str(ca_certificate))
+        return cmd
+
     @classmethod
     def create_credential_store_credential(
         cls,
diff --git a/tests/protocols/gmpnext/entities/credentials/__init__.py b/tests/protocols/gmpnext/entities/credentials/__init__.py
index 4a49c76ee..e1425d246 100644
--- a/tests/protocols/gmpnext/entities/credentials/__init__.py
+++ b/tests/protocols/gmpnext/entities/credentials/__init__.py
@@ -2,14 +2,22 @@
 #
 #  SPDX-License-Identifier: GPL-3.0-or-later
 
+from .test_create_active_directory_credential import (
+    GmpCreateActiveDirectoryCredentialTestMixin,
+)
 from .test_create_credential_store_credential import (
     GmpCreateCredentialStoreCredentialTestMixin,
 )
+from .test_modify_active_directory_credential import (
+    GmpModifyActiveDirectoryCredentialTestMixin,
+)
 from .test_modify_credential_store_credential import (
     GmpModifyCredentialStoreCredentialTestMixin,
 )
 
 __all__ = (
+    "GmpCreateActiveDirectoryCredentialTestMixin",
     "GmpCreateCredentialStoreCredentialTestMixin",
+    "GmpModifyActiveDirectoryCredentialTestMixin",
     "GmpModifyCredentialStoreCredentialTestMixin",
 )
diff --git a/tests/protocols/gmpnext/entities/credentials/test_create_active_directory_credential.py b/tests/protocols/gmpnext/entities/credentials/test_create_active_directory_credential.py
new file mode 100644
index 000000000..0238cd5ce
--- /dev/null
+++ b/tests/protocols/gmpnext/entities/credentials/test_create_active_directory_credential.py
@@ -0,0 +1,190 @@
+# SPDX-FileCopyrightText: 2026 Greenbone AG
+#
+# SPDX-License-Identifier: GPL-3.0-or-later
+#
+
+from gvm.errors import InvalidArgument, RequiredArgument
+
+
+class GmpCreateActiveDirectoryCredentialTestMixin:
+    def test_create_ad_credential(self):
+        self.gmp.create_active_directory_credential(
+            name="AD",
+            host="dc.example.org",
+            bind_dn="CN=Scanner,CN=Users,DC=example,DC=org",
+            base_dn="DC=example,DC=org",
+            bind_password="secret",
+            tls_mode="ldaps",
+        )
+
+        self.connection.send.has_been_called_with(
+            b"<create_credential>"
+            b"<name>AD</name>"
+            b"<type>ad</type>"
+            b"<host>dc.example.org</host>"
+            b"<bind_dn>CN=Scanner,CN=Users,DC=example,DC=org</bind_dn>"
+            b"<base_dn>DC=example,DC=org</base_dn>"
+            b"<bind_password>secret</bind_password>"
+            b"<tls_mode>ldaps</tls_mode>"
+            b"</create_credential>"
+        )
+
+    def test_create_ad_credential_with_starttls(self):
+        self.gmp.create_active_directory_credential(
+            name="AD",
+            host="dc.example.org",
+            bind_dn="CN=Scanner,CN=Users,DC=example,DC=org",
+            base_dn="DC=example,DC=org",
+            bind_password="secret",
+            tls_mode="starttls",
+        )
+
+        self.connection.send.has_been_called_with(
+            b"<create_credential>"
+            b"<name>AD</name>"
+            b"<type>ad</type>"
+            b"<host>dc.example.org</host>"
+            b"<bind_dn>CN=Scanner,CN=Users,DC=example,DC=org</bind_dn>"
+            b"<base_dn>DC=example,DC=org</base_dn>"
+            b"<bind_password>secret</bind_password>"
+            b"<tls_mode>starttls</tls_mode>"
+            b"</create_credential>"
+        )
+
+    def test_create_ad_credential_with_optional_arguments(self):
+        self.gmp.create_active_directory_credential(
+            name="AD",
+            host="dc.example.org",
+            bind_dn="CN=Scanner,CN=Users,DC=example,DC=org",
+            base_dn="DC=example,DC=org",
+            bind_password="secret<&",
+            tls_mode="ldaps",
+            comment="Directory",
+            port=636,
+            ca_certificate="PEM certificate",
+        )
+
+        self.connection.send.has_been_called_with(
+            b"<create_credential>"
+            b"<name>AD</name>"
+            b"<type>ad</type>"
+            b"<comment>Directory</comment>"
+            b"<host>dc.example.org</host>"
+            b"<bind_dn>CN=Scanner,CN=Users,DC=example,DC=org</bind_dn>"
+            b"<base_dn>DC=example,DC=org</base_dn>"
+            b"<bind_password>secret&lt;&amp;</bind_password>"
+            b"<tls_mode>ldaps</tls_mode>"
+            b"<port>636</port>"
+            b"<ca_certificate>PEM certificate</ca_certificate>"
+            b"</create_credential>"
+        )
+
+    def test_create_ad_credential_missing_name(self):
+        with self.assertRaises(RequiredArgument):
+            self.gmp.create_active_directory_credential(
+                name="",
+                host="dc.example.org",
+                bind_dn="CN=Scanner,CN=Users,DC=example,DC=org",
+                base_dn="DC=example,DC=org",
+                bind_password="secret",
+                tls_mode="ldaps",
+            )
+
+        with self.assertRaises(RequiredArgument):
+            self.gmp.create_active_directory_credential(
+                name=None,
+                host="dc.example.org",
+                bind_dn="CN=Scanner,CN=Users,DC=example,DC=org",
+                base_dn="DC=example,DC=org",
+                bind_password="secret",
+                tls_mode="ldaps",
+            )
+
+    def test_create_ad_credential_missing_host(self):
+        with self.assertRaises(RequiredArgument):
+            self.gmp.create_active_directory_credential(
+                name="AD",
+                host="",
+                bind_dn="CN=Scanner,CN=Users,DC=example,DC=org",
+                base_dn="DC=example,DC=org",
+                bind_password="secret",
+                tls_mode="ldaps",
+            )
+
+    def test_create_ad_credential_missing_bind_dn(self):
+        with self.assertRaises(RequiredArgument):
+            self.gmp.create_active_directory_credential(
+                name="AD",
+                host="dc.example.org",
+                bind_dn="",
+                base_dn="DC=example,DC=org",
+                bind_password="secret",
+                tls_mode="ldaps",
+            )
+
+    def test_create_ad_credential_missing_base_dn(self):
+        with self.assertRaises(RequiredArgument):
+            self.gmp.create_active_directory_credential(
+                name="AD",
+                host="dc.example.org",
+                bind_dn="CN=Scanner,CN=Users,DC=example,DC=org",
+                base_dn="",
+                bind_password="secret",
+                tls_mode="ldaps",
+            )
+
+    def test_create_ad_credential_missing_bind_password(self):
+        with self.assertRaises(RequiredArgument):
+            self.gmp.create_active_directory_credential(
+                name="AD",
+                host="dc.example.org",
+                bind_dn="CN=Scanner,CN=Users,DC=example,DC=org",
+                base_dn="DC=example,DC=org",
+                bind_password="",
+                tls_mode="ldaps",
+            )
+
+    def test_create_ad_credential_missing_tls_mode(self):
+        with self.assertRaises(RequiredArgument):
+            self.gmp.create_active_directory_credential(
+                name="AD",
+                host="dc.example.org",
+                bind_dn="CN=Scanner,CN=Users,DC=example,DC=org",
+                base_dn="DC=example,DC=org",
+                bind_password="secret",
+                tls_mode="",
+            )
+
+    def test_create_ad_credential_invalid_tls_mode(self):
+        with self.assertRaises(InvalidArgument):
+            self.gmp.create_active_directory_credential(
+                name="AD",
+                host="dc.example.org",
+                bind_dn="CN=Scanner,CN=Users,DC=example,DC=org",
+                base_dn="DC=example,DC=org",
+                bind_password="secret",
+                tls_mode="ldap",
+            )
+
+    def test_create_ad_credential_invalid_port(self):
+        with self.assertRaises(InvalidArgument):
+            self.gmp.create_active_directory_credential(
+                name="AD",
+                host="dc.example.org",
+                bind_dn="CN=Scanner,CN=Users,DC=example,DC=org",
+                base_dn="DC=example,DC=org",
+                bind_password="secret",
+                tls_mode="ldaps",
+                port=0,
+            )
+
+        with self.assertRaises(InvalidArgument):
+            self.gmp.create_active_directory_credential(
+                name="AD",
+                host="dc.example.org",
+                bind_dn="CN=Scanner,CN=Users,DC=example,DC=org",
+                base_dn="DC=example,DC=org",
+                bind_password="secret",
+                tls_mode="ldaps",
+                port=65536,
+            )
diff --git a/tests/protocols/gmpnext/entities/credentials/test_modify_active_directory_credential.py b/tests/protocols/gmpnext/entities/credentials/test_modify_active_directory_credential.py
new file mode 100644
index 000000000..2ef9e36f1
--- /dev/null
+++ b/tests/protocols/gmpnext/entities/credentials/test_modify_active_directory_credential.py
@@ -0,0 +1,140 @@
+# SPDX-FileCopyrightText: 2026 Greenbone AG
+#
+# SPDX-License-Identifier: GPL-3.0-or-later
+#
+
+from gvm.errors import InvalidArgument, RequiredArgument
+
+
+class GmpModifyActiveDirectoryCredentialTestMixin:
+    def test_modify_ad_credential(self):
+        self.gmp.modify_active_directory_credential(
+            credential_id="credential-id"
+        )
+
+        self.connection.send.has_been_called_with(
+            b'<modify_credential credential_id="credential-id"/>'
+        )
+
+    def test_modify_ad_credential_with_all_arguments(self):
+        self.gmp.modify_active_directory_credential(
+            credential_id="credential-id",
+            name="AD",
+            comment="Directory",
+            host="dc.example.org",
+            bind_dn="CN=Scanner,CN=Users,DC=example,DC=org",
+            base_dn="DC=example,DC=org",
+            bind_password="secret<&",
+            tls_mode="ldaps",
+            port=636,
+            ca_certificate="PEM certificate",
+        )
+
+        self.connection.send.has_been_called_with(
+            b'<modify_credential credential_id="credential-id">'
+            b"<name>AD</name>"
+            b"<comment>Directory</comment>"
+            b"<host>dc.example.org</host>"
+            b"<bind_dn>CN=Scanner,CN=Users,DC=example,DC=org</bind_dn>"
+            b"<base_dn>DC=example,DC=org</base_dn>"
+            b"<bind_password>secret&lt;&amp;</bind_password>"
+            b"<tls_mode>ldaps</tls_mode>"
+            b"<port>636</port>"
+            b"<ca_certificate>PEM certificate</ca_certificate>"
+            b"</modify_credential>"
+        )
+
+    def test_modify_ad_credential_with_bind_password(self):
+        self.gmp.modify_active_directory_credential(
+            credential_id="credential-id", bind_password="new-secret"
+        )
+
+        self.connection.send.has_been_called_with(
+            b'<modify_credential credential_id="credential-id">'
+            b"<bind_password>new-secret</bind_password>"
+            b"</modify_credential>"
+        )
+
+    def test_modify_ad_credential_clear_optional_arguments(self):
+        self.gmp.modify_active_directory_credential(
+            credential_id="credential-id",
+            comment="",
+            port="",
+            ca_certificate="",
+        )
+
+        self.connection.send.has_been_called_with(
+            b'<modify_credential credential_id="credential-id">'
+            b"<comment></comment>"
+            b"<port></port>"
+            b"<ca_certificate></ca_certificate>"
+            b"</modify_credential>"
+        )
+
+    def test_modify_ad_credential_missing_credential_id(self):
+        with self.assertRaises(RequiredArgument):
+            self.gmp.modify_active_directory_credential(None)
+
+        with self.assertRaises(RequiredArgument):
+            self.gmp.modify_active_directory_credential("")
+
+        with self.assertRaises(RequiredArgument):
+            self.gmp.modify_active_directory_credential(credential_id="")
+
+    def test_modify_ad_credential_empty_name(self):
+        with self.assertRaises(RequiredArgument):
+            self.gmp.modify_active_directory_credential(
+                credential_id="credential-id", name=""
+            )
+
+    def test_modify_ad_credential_empty_host(self):
+        with self.assertRaises(RequiredArgument):
+            self.gmp.modify_active_directory_credential(
+                credential_id="credential-id", host=""
+            )
+
+    def test_modify_ad_credential_empty_bind_dn(self):
+        with self.assertRaises(RequiredArgument):
+            self.gmp.modify_active_directory_credential(
+                credential_id="credential-id", bind_dn=""
+            )
+
+    def test_modify_ad_credential_empty_base_dn(self):
+        with self.assertRaises(RequiredArgument):
+            self.gmp.modify_active_directory_credential(
+                credential_id="credential-id", base_dn=""
+            )
+
+    def test_modify_ad_credential_empty_bind_password(self):
+        with self.assertRaises(RequiredArgument):
+            self.gmp.modify_active_directory_credential(
+                credential_id="credential-id", bind_password=""
+            )
+
+    def test_modify_ad_credential_empty_tls_mode(self):
+        with self.assertRaises(RequiredArgument):
+            self.gmp.modify_active_directory_credential(
+                credential_id="credential-id", tls_mode=""
+            )
+
+    def test_modify_ad_credential_invalid_tls_mode(self):
+        with self.assertRaises(InvalidArgument):
+            self.gmp.modify_active_directory_credential(
+                credential_id="credential-id", tls_mode="ldap"
+            )
+
+    def test_modify_ad_credential_invalid_port(self):
+        with self.assertRaises(InvalidArgument):
+            self.gmp.modify_active_directory_credential(
+                credential_id="credential-id", port=0
+            )
+
+        with self.assertRaises(InvalidArgument):
+            self.gmp.modify_active_directory_credential(
+                credential_id="credential-id", port=65536
+            )
+
+        with self.assertRaises(InvalidArgument):
+            self.gmp.modify_active_directory_credential(
+                credential_id="credential-id", port="636"
+            )
diff --git a/tests/protocols/gmpnext/entities/test_credentials.py b/tests/protocols/gmpnext/entities/test_credentials.py
index 6fd67390b..27724beef 100644
--- a/tests/protocols/gmpnext/entities/test_credentials.py
+++ b/tests/protocols/gmpnext/entities/test_credentials.py
@@ -1,4 +1,4 @@
-# SPDX-FileCopyrightText: 2023-2025 Greenbone AG
+# SPDX-FileCopyrightText: 2023-2026 Greenbone AG
 #
 # SPDX-License-Identifier: GPL-3.0-or-later
 #
@@ -13,7 +13,9 @@
     GmpModifyCredentialTestMixin,
 )
 from ..entities.credentials import (
+    GmpCreateActiveDirectoryCredentialTestMixin,
     GmpCreateCredentialStoreCredentialTestMixin,
+    GmpModifyActiveDirectoryCredentialTestMixin,
     GmpModifyCredentialStoreCredentialTestMixin,
 )
 
@@ -24,6 +26,7 @@ class GMPCloneCredentialTestCase(GmpCloneCredentialTestMixin, GMPTestCase):
 
 class GMPCreateCredentialTestCase(
     GmpCreateCredentialTestMixin,
+    GmpCreateActiveDirectoryCredentialTestMixin,
     GmpCreateCredentialStoreCredentialTestMixin,
     GMPTestCase,
 ):
@@ -44,6 +47,7 @@ class GMPGetCredentialsTestCase(GmpGetCredentialsTestMixin, GMPTestCase):
 
 class GMPModifyCredentialTestCase(
     GmpModifyCredentialTestMixin,
+    GmpModifyActiveDirectoryCredentialTestMixin,
     GmpModifyCredentialStoreCredentialTestMixin,
     GMPTestCase,
 ):