diff --git a/config/autoload/doctrine.local.development.php.dist b/config/autoload/doctrine.local.development.php.dist
index dc6f9addf0..c0295ca50b 100644
--- a/config/autoload/doctrine.local.development.php.dist
+++ b/config/autoload/doctrine.local.development.php.dist
@@ -20,6 +20,7 @@
 
 declare(strict_types=1);
 
+use Decision\Extensions\Doctrine\MeetingTypesType;
 use Doctrine\DBAL\Driver\PDO\MySQL\Driver;
 
 return [
@@ -41,6 +42,9 @@ return [
                         PDO::MYSQL_ATTR_SSL_VERIFY_SERVER_CERT => true,
                     ] : [],
                 ],
+                'doctrineTypeMappings' => [
+                    MeetingTypesType::NAME => MeetingTypesType::NAME,
+                ],
             ],
         ],
         // Configuration details for the ORM.
@@ -73,6 +77,9 @@ return [
                 ],
                 // Second level cache configuration (see doc to learn about configuration)
                 'second_level_cache' => [],
+                'types' => [
+                    MeetingTypesType::NAME => MeetingTypesType::class,
+                ],
             ],
         ],
         'migrations_configuration' => [
diff --git a/module/Application/src/Extensions/Doctrine/BackedEnumType.php b/module/Application/src/Extensions/Doctrine/BackedEnumType.php
new file mode 100644
index 0000000000..1549dba82c
--- /dev/null
+++ b/module/Application/src/Extensions/Doctrine/BackedEnumType.php
@@ -0,0 +1,72 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Application\Extensions\Doctrine;
+
+use BackedEnum;
+use Doctrine\DBAL\Platforms\AbstractPlatform;
+use Doctrine\DBAL\Types\Type;
+
+use function call_user_func;
+
+/**
+ * Custom mapping type for Doctrine DBAL to directly support enums in a database without having to use a native type.
+ *
+ * It is necessary to use this custom mapping type due to an apparent bug in the value conversion layer in DBAL when
+ * using trying to construct our (Sub)Decisions in specific scenarios (e.g. seeding the database).
+ *
+ * Due to the `final` marking of the constructor we cannot initialise {@link BackedEnumType::$enumClass} and
+ * {@link BackedEnumType::$name}. As such, we need to override these when creating specific mapping types.
+ *
+ * @template T of BackedEnum
+ */
+abstract class BackedEnumType extends Type
+{
+    /**
+     * @var class-string<T> $enumClass
+     * @required
+     */
+    public string $enumClass;
+
+    /**
+     * @required
+     */
+    public const string NAME = '';
+
+    /**
+     * {@inheritDoc}
+     *
+     * @phpcsSuppress SlevomatCodingStandard.TypeHints.ParameterTypeHint.MissingTraversableTypeHintSpecification
+     */
+    public function getSQLDeclaration(
+        array $column,
+        AbstractPlatform $platform,
+    ): string {
+        return $platform->getStringTypeDeclarationSQL($column);
+    }
+
+    /**
+     * @return T|null
+     */
+    public function convertToPHPValue(
+        mixed $value,
+        AbstractPlatform $platform,
+    ) {
+        if (empty($value)) {
+            return null;
+        }
+
+        return call_user_func([$this->enumClass, 'from'], $value);
+    }
+
+    /**
+     * @phpcsSuppress SlevomatCodingStandard.TypeHints.ReturnTypeHint.MissingAnyTypeHint
+     */
+    public function convertToDatabaseValue(
+        mixed $value,
+        AbstractPlatform $platform,
+    ) {
+        return $value instanceof $this->enumClass ? $value->value : $value;
+    }
+}
diff --git a/module/Decision/src/Extensions/Doctrine/MeetingTypesType.php b/module/Decision/src/Extensions/Doctrine/MeetingTypesType.php
new file mode 100644
index 0000000000..ae9b3f9243
--- /dev/null
+++ b/module/Decision/src/Extensions/Doctrine/MeetingTypesType.php
@@ -0,0 +1,23 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Decision\Extensions\Doctrine;
+
+use Application\Extensions\Doctrine\BackedEnumType;
+use Decision\Model\Enums\MeetingTypes;
+
+/**
+ * @extends BackedEnumType<MeetingTypes>
+ */
+class MeetingTypesType extends BackedEnumType
+{
+    public string $enumClass = MeetingTypes::class;
+
+    public const string NAME = 'meeting_types';
+
+    public function getName(): string
+    {
+        return self::NAME;
+    }
+}
diff --git a/module/Decision/src/Model/Decision.php b/module/Decision/src/Model/Decision.php
index 75bb14ada7..b54e7bda92 100644
--- a/module/Decision/src/Model/Decision.php
+++ b/module/Decision/src/Model/Decision.php
@@ -4,6 +4,7 @@
 
 namespace Decision\Model;
 
+use Decision\Extensions\Doctrine\MeetingTypesType;
 use Decision\Model\Enums\MeetingTypes;
 use Decision\Model\SubDecision\Annulment;
 use Doctrine\Common\Collections\ArrayCollection;
@@ -48,10 +49,7 @@ class Decision
      * NOTE: This is a hack to make the meeting a primary key here.
      */
     #[Id]
-    #[Column(
-        type: 'string',
-        enumType: MeetingTypes::class,
-    )]
+    #[Column(type: MeetingTypesType::NAME)]
     protected MeetingTypes $meeting_type;
 
     /**
diff --git a/module/Decision/src/Model/Meeting.php b/module/Decision/src/Model/Meeting.php
index 4908f9e167..d96cb69cbb 100644
--- a/module/Decision/src/Model/Meeting.php
+++ b/module/Decision/src/Model/Meeting.php
@@ -5,6 +5,7 @@
 namespace Decision\Model;
 
 use DateTime;
+use Decision\Extensions\Doctrine\MeetingTypesType;
 use Decision\Model\Enums\MeetingTypes;
 use Doctrine\Common\Collections\ArrayCollection;
 use Doctrine\Common\Collections\Collection;
@@ -25,10 +26,7 @@ class Meeting
      * Meeting type.
      */
     #[Id]
-    #[Column(
-        type: 'string',
-        enumType: MeetingTypes::class,
-    )]
+    #[Column(type: MeetingTypesType::NAME)]
     protected MeetingTypes $type;
 
     /**
diff --git a/module/Decision/src/Model/MeetingMinutes.php b/module/Decision/src/Model/MeetingMinutes.php
index 0fbd385b60..bfc8376ad5 100644
--- a/module/Decision/src/Model/MeetingMinutes.php
+++ b/module/Decision/src/Model/MeetingMinutes.php
@@ -5,6 +5,7 @@
 namespace Decision\Model;
 
 use Application\Model\Traits\TimestampableTrait;
+use Decision\Extensions\Doctrine\MeetingTypesType;
 use Decision\Model\Enums\MeetingTypes;
 use Doctrine\ORM\Mapping\Column;
 use Doctrine\ORM\Mapping\Entity;
@@ -27,10 +28,7 @@ class MeetingMinutes implements ResourceInterface
      * Meeting type.
      */
     #[Id]
-    #[Column(
-        type: 'string',
-        enumType: MeetingTypes::class,
-    )]
+    #[Column(type: MeetingTypesType::NAME)]
     protected MeetingTypes $meeting_type;
 
     /**
diff --git a/module/Decision/src/Model/SubDecision.php b/module/Decision/src/Model/SubDecision.php
index 12e356d247..579367097c 100644
--- a/module/Decision/src/Model/SubDecision.php
+++ b/module/Decision/src/Model/SubDecision.php
@@ -4,6 +4,7 @@
 
 namespace Decision\Model;
 
+use Decision\Extensions\Doctrine\MeetingTypesType;
 use Decision\Model\Enums\MeetingTypes;
 use Decision\Model\SubDecision\Abrogation;
 use Decision\Model\SubDecision\Annulment;
@@ -99,10 +100,7 @@ abstract class SubDecision
      * NOTE: This is a hack to make the decision a primary key here.
      */
     #[Id]
-    #[Column(
-        type: 'string',
-        enumType: MeetingTypes::class,
-    )]
+    #[Column(type: MeetingTypesType::NAME)]
     protected MeetingTypes $meeting_type;
 
     /**
diff --git a/module/Decision/test/Seeder/DecisionFixture.php b/module/Decision/test/Seeder/DecisionFixture.php
new file mode 100644
index 0000000000..ec2dc76efb
--- /dev/null
+++ b/module/Decision/test/Seeder/DecisionFixture.php
@@ -0,0 +1,276 @@
+<?php
+
+declare(strict_types=1);
+
+namespace DecisionTest\Seeder;
+
+use Decision\Model\Decision;
+use Decision\Model\Enums\OrganTypes;
+use Decision\Model\Meeting;
+use Decision\Model\Member;
+use Decision\Model\Organ;
+use Decision\Model\OrganMember;
+use Decision\Model\SubDecision\Discharge;
+use Decision\Model\SubDecision\Foundation;
+use Decision\Model\SubDecision\Installation;
+use Doctrine\Common\DataFixtures\AbstractFixture;
+use Doctrine\Common\DataFixtures\DependentFixtureInterface;
+use Doctrine\Persistence\ObjectManager;
+
+use function implode;
+use function range;
+use function sprintf;
+use function ucfirst;
+
+class DecisionFixture extends AbstractFixture implements DependentFixtureInterface
+{
+    public function load(ObjectManager $manager): void
+    {
+        // Installment of GETÉST.
+        $decision = new Decision();
+        $decision->setMeeting($this->getReference('meeting-BV-0', Meeting::class));
+        $decision->setPoint(1);
+        $decision->setNumber(1);
+        $decision->setContent('');
+
+        $manager->persist($decision);
+        $this->addReference('decision-BV-0-' . $decision->getPoint() . '-' . $decision->getNumber(), $decision);
+
+        $sequence = 1;
+        $iSubdecisions = [];
+
+        $foundation = new Foundation();
+        $foundation->setAbbr('GETÉST');
+        $foundation->setName('GEWIS\'ers Testen Éigenlijk Structureel Te-weinig');
+        $foundation->setOrganType(OrganTypes::Committee);
+        $foundation->setDecision($decision);
+        $foundation->setSequence($sequence);
+        $foundation->setContent(sprintf(
+            '%s %s met afkorting %s wordt opgericht.',
+            ucfirst($foundation->getOrganType()->value), // shortcut as getting the translator for `getName()` sucks.
+            $foundation->getName(),
+            $foundation->getAbbr(),
+        ));
+
+        $manager->persist($foundation);
+        $iSubdecisions[] = $foundation;
+        $this->addReference('foundation-' . $foundation->getSequence(), $foundation);
+
+        // phpcs:disable SlevomatCodingStandard.ControlStructures.EarlyExit.EarlyExitNotUsed
+        foreach (range(8005, 8024) as $lidnr) {
+            $sequence++;
+            $iSubdecisions[] = $this->createInstallation(
+                'Lid',
+                $lidnr,
+                $sequence,
+                $foundation,
+                $decision,
+                $manager,
+            );
+
+            // Additional roles for specific members.
+            if (8005 === $lidnr) {
+                $sequence++;
+                $iSubdecisions[] = $this->createInstallation(
+                    'Voorzitter',
+                    $lidnr,
+                    $sequence,
+                    $foundation,
+                    $decision,
+                    $manager,
+                );
+            }
+
+            if (8006 === $lidnr) {
+                $sequence++;
+                $iSubdecisions[] = $this->createInstallation(
+                    'Secretaris',
+                    $lidnr,
+                    $sequence,
+                    $foundation,
+                    $decision,
+                    $manager,
+                );
+            }
+
+            // Will be discharged.
+            if (8020 === $lidnr) {
+                $sequence++;
+                $iSubdecisions[] = $this->createInstallation(
+                    'Penningmeester',
+                    $lidnr,
+                    $sequence,
+                    $foundation,
+                    $decision,
+                    $manager,
+                );
+            }
+        }
+
+        // phpcs:enable SlevomatCodingStandard.ControlStructures.EarlyExit.EarlyExitNotUsed
+
+        $content = [];
+        foreach ($decision->getSubdecisions() as $subdecision) {
+            $content[] = $subdecision->getContent();
+        }
+
+        $decision->setContent(implode('. ', $content));
+        $manager->persist($decision);
+
+        $manager->flush();
+
+        // Discharge of members of GETEST
+        $decision = new Decision();
+        $decision->setMeeting($this->getReference('meeting-BV-1', Meeting::class));
+        $decision->setPoint(1);
+        $decision->setNumber(1);
+        $decision->setContent('');
+
+        $manager->persist($decision);
+        $this->addReference('decision-BV-1-' . $decision->getPoint() . '-' . $decision->getNumber(), $decision);
+
+        $sequence = 1;
+        $dSubdecisions = [];
+
+        foreach (range(8020, 8024) as $lidnr) {
+            // Order of discharge matters, the discharge from a special function comes before `Lid`.
+            if (8020 === $lidnr) {
+                $dSubdecisions[] = $this->createDischarge(
+                    $sequence,
+                    $sequence + 18, // TODO: find a better way to calculate this.
+                    $decision,
+                    $manager,
+                );
+                $sequence++;
+            }
+
+            $dSubdecisions[] = $this->createDischarge(
+                $sequence,
+                $sequence + 18, // TODO: find a better way to calculate this.
+                $decision,
+                $manager,
+            );
+            $sequence++;
+        }
+
+        $content = [];
+        foreach ($decision->getSubdecisions() as $dSubdecision) {
+            $content[] = $dSubdecision->getContent();
+        }
+
+        $decision->setContent(implode('. ', $content));
+        $manager->persist($decision);
+
+        $manager->flush();
+
+        // Creation of the actual organ and its members here as well. This is because Doctrine sucks and breaks in the
+        // opposite way with the custom mapping type.
+
+        // Foundation
+        $organ = new Organ();
+        $organ->setName($foundation->getName());
+        $organ->setAbbr($foundation->getAbbr());
+        $organ->setFoundation($foundation);
+        $organ->setType($foundation->getOrganType());
+        $organ->setFoundationDate($foundation->getDecision()->getMeeting()->getDate());
+
+        $manager->persist($organ);
+        $manager->flush();
+
+        // Installations
+        foreach ($iSubdecisions as $installation) {
+            if (!($installation instanceof Installation)) {
+                continue;
+            }
+
+            $organMember = new OrganMember();
+            $organMember->setOrgan($organ);
+            $organMember->setMember($installation->getMember());
+            $organMember->setInstallation($installation);
+            $organMember->setFunction($installation->getFunction());
+            $organMember->setInstallDate($installation->getFoundation()->getDecision()->getMeeting()->getDate());
+
+            $manager->persist($organMember);
+            $this->addReference('organMember-' . $installation->getSequence(), $organMember);
+        }
+
+        $manager->flush();
+
+        // Discharges
+        foreach ($dSubdecisions as $discharge) {
+            $organMember = $this->getReference(
+                'organMember-' . $discharge->getInstallation()->getSequence(),
+                OrganMember::class,
+            );
+            $organMember->setDischargeDate($discharge->getDecision()->getMeeting()->getDate());
+
+            $manager->persist($organMember);
+        }
+
+        $manager->flush();
+    }
+
+    private function createInstallation(
+        string $function,
+        int $lidnr,
+        int $sequence,
+        Foundation $foundation,
+        Decision $decision,
+        ObjectManager $manager,
+    ): Installation {
+        $installation = new Installation();
+        $installation->setFunction($function);
+        $installation->setMember($this->getReference('member-' . $lidnr, Member::class));
+        $installation->setSequence($sequence);
+        $installation->setFoundation($foundation);
+        $installation->setDecision($decision);
+        $installation->setContent(
+            sprintf(
+                '%s wordt geïnstalleerd als %s van %s',
+                $installation->getMember()->getFullName(),
+                $installation->getFunction(),
+                $installation->getFoundation()->getAbbr(),
+            ),
+        );
+
+        $manager->persist($installation);
+        $this->addReference('installation-' . $installation->getSequence(), $installation);
+
+        return $installation;
+    }
+
+    private function createDischarge(
+        int $sequence,
+        int $installationSequence,
+        Decision $decision,
+        ObjectManager $manager,
+    ): Discharge {
+        $discharge = new Discharge();
+        $discharge->setInstallation($this->getReference('installation-' . $installationSequence, Installation::class));
+        $discharge->setSequence($sequence);
+        $discharge->setDecision($decision);
+        $discharge->setContent(
+            sprintf(
+                '%s wordt gedechargeerd als %s van %s',
+                $discharge->getInstallation()->getMember()->getFullName(),
+                $discharge->getInstallation()->getFunction(),
+                $discharge->getInstallation()->getFoundation()->getAbbr(),
+            ),
+        );
+
+        $manager->persist($discharge);
+        $this->addReference('discharge-' . $discharge->getSequence(), $discharge);
+
+        return $discharge;
+    }
+
+    /**
+     * @return class-string[]
+     */
+    public function getDependencies(): array
+    {
+        return [
+            MeetingFixture::class,
+        ];
+    }
+}