diff --git a/webapp/migrations/Version20231124162457.php b/webapp/migrations/Version20231124162457.php
new file mode 100644
index 00000000000..8b99aed5a0b
--- /dev/null
+++ b/webapp/migrations/Version20231124162457.php
@@ -0,0 +1,42 @@
+<?php
+
+declare(strict_types=1);
+
+namespace DoctrineMigrations;
+
+use Doctrine\DBAL\Schema\Schema;
+use Doctrine\Migrations\AbstractMigration;
+
+/**
+ * Auto-generated Migration: Please modify to your needs!
+ */
+final class Version20231124162457 extends AbstractMigration
+{
+    public function getDescription(): string
+    {
+        return 'Split submission file contents from submission files';
+    }
+
+    public function up(Schema $schema): void
+    {
+        // this up() migration is auto-generated, please modify it to your needs
+        $this->addSql('CREATE TABLE submission_file_content (submitfileid INT UNSIGNED NOT NULL COMMENT \'Submission file ID\', sourcecode LONGBLOB NOT NULL COMMENT \'Submission file sourcecode(DC2Type:blobtext)\', PRIMARY KEY(submitfileid)) DEFAULT CHARACTER SET utf8mb4 COLLATE `utf8mb4_unicode_ci` ENGINE = InnoDB COMMENT = \'Stores contents of submission files\' ');
+        $this->addSql('ALTER TABLE submission_file_content ADD CONSTRAINT FK_5846B4F7834A5B68 FOREIGN KEY (submitfileid) REFERENCES submission_file (submitfileid) ON DELETE CASCADE');
+        $this->addSql('INSERT INTO submission_file_content (submitfileid, sourcecode) SELECT submitfileid, sourcecode FROM submission_file');
+        $this->addSql('ALTER TABLE submission_file DROP sourcecode');
+    }
+
+    public function down(Schema $schema): void
+    {
+        // this down() migration is auto-generated, please modify it to your needs
+        $this->addSql('ALTER TABLE submission_file ADD sourcecode LONGBLOB NOT NULL COMMENT \'Full source code(DC2Type:blobtext)\'');
+        $this->addSql('UPDATE submission_file INNER JOIN submission_file_content USING (submitfileid) SET submission_file.sourcecode = submission_file_content.sourcecode');
+        $this->addSql('ALTER TABLE submission_file_content DROP FOREIGN KEY FK_5846B4F7834A5B68');
+        $this->addSql('DROP TABLE submission_file_content');
+    }
+
+    public function isTransactional(): bool
+    {
+        return false;
+    }
+}
diff --git a/webapp/src/Controller/API/JudgehostController.php b/webapp/src/Controller/API/JudgehostController.php
index dfb75098fcb..e6ec7f986b8 100644
--- a/webapp/src/Controller/API/JudgehostController.php
+++ b/webapp/src/Controller/API/JudgehostController.php
@@ -1335,7 +1335,8 @@ private function getSourceFiles(string $id): array
     {
         $queryBuilder = $this->em->createQueryBuilder()
             ->from(SubmissionFile::class, 'f')
-            ->select('f')
+            ->join('f.content', 'c')
+            ->select('f', 'c')
             ->andWhere('f.submission = :submitid')
             ->setParameter('submitid', $id)
             ->orderBy('f.ranknumber');
@@ -1351,7 +1352,7 @@ private function getSourceFiles(string $id): array
         foreach ($files as $file) {
             $result[]   = [
                 'filename' => $file->getFilename(),
-                'content' => base64_encode($file->getSourcecode()),
+                'content' => base64_encode($file->getContent()->getSourcecode()),
             ];
         }
         return $result;
diff --git a/webapp/src/Controller/API/SubmissionController.php b/webapp/src/Controller/API/SubmissionController.php
index 7da7bcfeb70..391bfc01a6a 100644
--- a/webapp/src/Controller/API/SubmissionController.php
+++ b/webapp/src/Controller/API/SubmissionController.php
@@ -514,7 +514,8 @@ public function getSubmissionSourceCodeAction(Request $request, string $id): arr
         $queryBuilder = $this->em->createQueryBuilder()
             ->from(SubmissionFile::class, 'f')
             ->join('f.submission', 's')
-            ->select('f, s')
+            ->join('.f.content', 'c')
+            ->select('f, s, c')
             ->andWhere('s.contest = :cid')
             ->andWhere('s.submitid = :submitid')
             ->setParameter('cid', $this->getContestId($request))
@@ -534,7 +535,7 @@ public function getSubmissionSourceCodeAction(Request $request, string $id): arr
                 'id' => (string)$file->getSubmitfileid(),
                 'submission_id' => (string)$file->getSubmission()->getSubmitid(),
                 'filename' => $file->getFilename(),
-                'source' => base64_encode($file->getSourcecode()),
+                'source' => base64_encode($file->getContent()->getSourcecode()),
             ];
         }
         return $result;
diff --git a/webapp/src/Controller/Jury/ProblemController.php b/webapp/src/Controller/Jury/ProblemController.php
index 65f81d7510a..54f8ab663ad 100644
--- a/webapp/src/Controller/Jury/ProblemController.php
+++ b/webapp/src/Controller/Jury/ProblemController.php
@@ -356,7 +356,7 @@ public function exportAction(int $problemId): StreamedResponse
             $directory = sprintf('submissions/%s/s%d/', $problemResult, $solution->getSubmitid());
             /** @var SubmissionFile $source */
             foreach ($solution->getFiles() as $source) {
-                $zip->addFromString($directory . $source->getFilename(), $source->getSourcecode());
+                $zip->addFromString($directory . $source->getFilename(), $source->getContent()->getSourcecode());
             }
         }
         $zip->close();
diff --git a/webapp/src/Controller/Jury/SubmissionController.php b/webapp/src/Controller/Jury/SubmissionController.php
index d92a3e281e8..da33de66ece 100644
--- a/webapp/src/Controller/Jury/SubmissionController.php
+++ b/webapp/src/Controller/Jury/SubmissionController.php
@@ -197,7 +197,7 @@ public function viewAction(
             ->leftJoin('s.files', 'f')
             ->leftJoin('s.external_judgements', 'ej', Join::WITH, 'ej.valid = 1')
             ->leftJoin('s.contest_problem', 'cp')
-            ->select('s', 't', 'p', 'l', 'c', 'partial f.{submitfileid, filename}', 'cp', 'ej')
+            ->select('s', 't', 'p', 'l', 'c', 'f', 'cp', 'ej')
             ->andWhere('s.submitid = :submitid')
             ->setParameter('submitid', $submitId)
             ->getQuery()
@@ -697,7 +697,8 @@ public function sourceAction(
             /** @var SubmissionFile|null $file */
             $file = $this->em->createQueryBuilder()
                 ->from(SubmissionFile::class, 'file')
-                ->select('file')
+                ->join('file.content', 'content')
+                ->select('file, content')
                 ->andWhere('file.ranknumber = :ranknumber')
                 ->andWhere('file.submission = :submission')
                 ->setParameter('ranknumber', $fetch)
@@ -713,8 +714,8 @@ public function sourceAction(
             $response->headers->set('Content-Type',
                                     sprintf('text/plain; name="%s"; charset="utf-8"', $file->getFilename()));
             $response->headers->set('Content-Disposition', sprintf('attachment; filename="%s"', $file->getFilename()));
-            $response->headers->set('Content-Length', (string)strlen($file->getSourcecode()));
-            $response->setContent($file->getSourcecode());
+            $response->headers->set('Content-Length', (string)strlen($file->getContent()->getSourcecode()));
+            $response->setContent($file->getContent()->getSourcecode());
 
             return $response;
         }
@@ -722,7 +723,8 @@ public function sourceAction(
         /** @var SubmissionFile[] $files */
         $files = $this->em->createQueryBuilder()
             ->from(SubmissionFile::class, 'file')
-            ->select('file')
+            ->join('file.content', 'content')
+            ->select('file, content')
             ->andWhere('file.submission = :submission')
             ->setParameter('submission', $submission)
             ->orderBy('file.ranknumber')
@@ -738,7 +740,8 @@ public function sourceAction(
             /** @var SubmissionFile[] $files */
             $originalFiles = $this->em->createQueryBuilder()
                 ->from(SubmissionFile::class, 'file')
-                ->select('file')
+                ->join('file.content', 'content')
+                ->select('file, content')
                 ->andWhere('file.submission = :submission')
                 ->setParameter('submission', $originalSubmission)
                 ->orderBy('file.ranknumber')
@@ -782,7 +785,8 @@ public function sourceAction(
         /** @var SubmissionFile[] $files */
         $oldFiles = $this->em->createQueryBuilder()
             ->from(SubmissionFile::class, 'file')
-            ->select('file')
+            ->join('file.content', 'content')
+            ->select('file, content')
             ->andWhere('file.submission = :submission')
             ->setParameter('submission', $oldSubmission)
             ->orderBy('file.ranknumber')
@@ -818,7 +822,8 @@ public function editSourceAction(Request $request, Submission $submission, #[Map
         /** @var SubmissionFile[] $files */
         $files = $this->em->createQueryBuilder()
             ->from(SubmissionFile::class, 'file')
-            ->select('file')
+            ->join('file.content', 'content')
+            ->select('file, content')
             ->andWhere('file.submission = :submission')
             ->setParameter('submission', $submission)
             ->orderBy('file.ranknumber')
@@ -832,7 +837,7 @@ public function editSourceAction(Request $request, Submission $submission, #[Map
         ];
 
         foreach ($files as $file) {
-            $data['source' . $file->getRank()] = $file->getSourcecode();
+            $data['source' . $file->getRank()] = $file->getContent()->getSourcecode();
         }
 
         $formBuilder = $this->createFormBuilder($data)
@@ -1082,6 +1087,10 @@ public function verifyShadowDifferenceAction(
         return $this->redirectToLocalReferrer($this->router, $request, $redirect);
     }
 
+    /**
+     * @param SubmissionFile[] $files
+     * @param SubmissionFile[] $oldFiles
+     */
     protected function determineFileChanged(array $files, array $oldFiles): array
     {
         $result = [
@@ -1098,7 +1107,7 @@ protected function determineFileChanged(array $files, array $oldFiles): array
         foreach ($files as $newfile) {
             foreach ($oldFiles as $oldFile) {
                 if ($newfile->getFilename() === $oldFile->getFilename()) {
-                    if ($oldFile->getSourcecode() === $newfile->getSourcecode()) {
+                    if ($oldFile->getContent()->getSourcecode() === $newfile->getContent()->getSourcecode()) {
                         $result['unchanged'][] = $newfile->getFilename();
                     } else {
                         $result['changed'][]      = $newfile->getFilename();
diff --git a/webapp/src/Entity/SubmissionFile.php b/webapp/src/Entity/SubmissionFile.php
index a23c39f92a1..73cb1ae9ad1 100644
--- a/webapp/src/Entity/SubmissionFile.php
+++ b/webapp/src/Entity/SubmissionFile.php
@@ -2,6 +2,8 @@
 
 namespace App\Entity;
 
+use Doctrine\Common\Collections\ArrayCollection;
+use Doctrine\Common\Collections\Collection;
 use Doctrine\ORM\Mapping as ORM;
 
 /**
@@ -36,8 +38,25 @@ class SubmissionFile
     #[ORM\JoinColumn(name: 'submitid', referencedColumnName: 'submitid', onDelete: 'CASCADE')]
     private Submission $submission;
 
-    #[ORM\Column(type: 'blobtext', options: ['comment' => 'Full source code'])]
-    private string $sourcecode;
+    /**
+     * @var Collection<int, SubmissionFileContent>
+     *
+     * We use a OneToMany instead of a OneToOne here, because otherwise this
+     * relation will always be loaded. See the commit message of commit
+     * 9e421f96691ec67ed62767fe465a6d8751edd884 for a more elaborate explanation
+     */
+    #[ORM\OneToMany(
+        mappedBy: 'submissionFile',
+        targetEntity: SubmissionFileContent::class,
+        cascade: ['persist'],
+        orphanRemoval: true
+    )]
+    private Collection $content;
+
+    public function __construct()
+    {
+        $this->content = new ArrayCollection();
+    }
 
     public function getSubmitfileid(): int
     {
@@ -77,14 +96,17 @@ public function getSubmission(): Submission
         return $this->submission;
     }
 
-    public function setSourcecode(string $sourcecode): SubmissionFile
+    public function setContent(SubmissionFileContent $content): self
     {
-        $this->sourcecode = $sourcecode;
+        $this->content->clear();
+        $this->content->add($content);
+        $content->setSubmissionFile($this);
+
         return $this;
     }
 
-    public function getSourcecode(): string
+    public function getContent(): ?SubmissionFileContent
     {
-        return $this->sourcecode;
+        return $this->content->first() ?: null;
     }
 }
diff --git a/webapp/src/Entity/SubmissionFileContent.php b/webapp/src/Entity/SubmissionFileContent.php
new file mode 100644
index 00000000000..29452f746b7
--- /dev/null
+++ b/webapp/src/Entity/SubmissionFileContent.php
@@ -0,0 +1,51 @@
+<?php declare(strict_types=1);
+
+namespace App\Entity;
+
+use Doctrine\ORM\Mapping as ORM;
+
+#[ORM\Entity]
+#[ORM\Table(options: [
+    'collation' => 'utf8mb4_unicode_ci',
+    'charset' => 'utf8mb4',
+    'comment' => 'Stores contents of submission files',
+])]
+class SubmissionFileContent
+{
+    /**
+     * We use a ManyToOne instead of a OneToOne here, because otherwise the
+     * reverse of this relation will always be loaded. See the commit message of commit
+     * 9e421f96691ec67ed62767fe465a6d8751edd884 for a more elaborate explanation.
+     */
+    #[ORM\Id]
+    #[ORM\ManyToOne(inversedBy: 'content')]
+    #[ORM\JoinColumn(name: 'submitfileid', referencedColumnName: 'submitfileid', onDelete: 'CASCADE')]
+    private SubmissionFile $submissionFile;
+
+    #[ORM\Column(type: 'blobtext', options: ['comment' => 'Submission file sourcecode'])]
+    private string $sourcecode;
+
+    public function getSubmissionFile(): SubmissionFile
+    {
+        return $this->submissionFile;
+    }
+
+    public function setSubmissionFile(SubmissionFile $submissionFile): self
+    {
+        $this->submissionFile = $submissionFile;
+
+        return $this;
+    }
+
+    public function getSourcecode(): string
+    {
+        return $this->sourcecode;
+    }
+
+    public function setSourcecode(string $sourcecode): self
+    {
+        $this->sourcecode = $sourcecode;
+
+        return $this;
+    }
+}
diff --git a/webapp/src/Service/SubmissionService.php b/webapp/src/Service/SubmissionService.php
index 33b10ce20eb..9b989e6ba7c 100644
--- a/webapp/src/Service/SubmissionService.php
+++ b/webapp/src/Service/SubmissionService.php
@@ -10,6 +10,7 @@
 use App\Entity\Problem;
 use App\Entity\Submission;
 use App\Entity\SubmissionFile;
+use App\Entity\SubmissionFileContent;
 use App\Entity\Team;
 use App\Entity\User;
 use App\Utils\FreezeData;
@@ -610,11 +611,13 @@ public function submitSolution(
         $this->em->persist($submission);
 
         foreach ($files as $rank => $file) {
+            $submissionFileContent = (new SubmissionFileContent())
+                ->setSourcecode(file_get_contents($file->getRealPath()));
             $submissionFile = new SubmissionFile();
             $submissionFile
                 ->setFilename($file->getClientOriginalName())
                 ->setRank($rank)
-                ->setSourcecode(file_get_contents($file->getRealPath()));
+                ->setContent($submissionFileContent);
             $submissionFile->setSubmission($submission);
             $this->em->persist($submissionFile);
         }
@@ -767,7 +770,7 @@ public function getSubmissionZipResponse(Submission $submission): StreamedRespon
             throw new ServiceUnavailableHttpException(null, "Could not create temporary zip file.");
         }
         foreach ($files as $file) {
-            $zip->addFromString($file->getFilename(), $file->getSourcecode());
+            $zip->addFromString($file->getFilename(), $file->getContent()->getSourcecode());
         }
         $zip->close();
 
diff --git a/webapp/src/Twig/TwigExtension.php b/webapp/src/Twig/TwigExtension.php
index 7b6189ed66e..6e57df56a82 100644
--- a/webapp/src/Twig/TwigExtension.php
+++ b/webapp/src/Twig/TwigExtension.php
@@ -877,7 +877,7 @@ protected function parseSourceDiff(string $difftext): string
     public function showDiff(SubmissionFile $newFile, SubmissionFile $oldFile): string
     {
         $differ = new Differ;
-        return $this->parseSourceDiff($differ->diff($oldFile->getSourcecode(), $newFile->getSourcecode()));
+        return $this->parseSourceDiff($differ->diff($oldFile->getContent()->getSourcecode(), $newFile->getContent()->getSourcecode()));
     }
 
     public function printContestStart(Contest $contest): string
diff --git a/webapp/templates/jury/submission_edit_source.html.twig b/webapp/templates/jury/submission_edit_source.html.twig
index fda25e00f1d..2ac827584fe 100644
--- a/webapp/templates/jury/submission_edit_source.html.twig
+++ b/webapp/templates/jury/submission_edit_source.html.twig
@@ -32,7 +32,7 @@
 
             <div class="tab-pane fade {% if (selected is null and loop.first) or selected == file.rank %}show active{% endif %}"
                  id="source-{{ file.rank }}" role="tabpanel">
-                {{ file.sourcecode | codeEditor(idx, submission.language.aceLanguage, true, 'form_source' ~ file.rank) }}
+                {{ file.conte.tsourcecode | codeEditor(idx, submission.language.aceLanguage, true, 'form_source' ~ file.rank) }}
                 <script>
                     $(function () {
                         $('#form_source{{ file.rank }}').closest('div.mb-3').hide();
diff --git a/webapp/templates/jury/submission_source.html.twig b/webapp/templates/jury/submission_source.html.twig
index 0235a6c41a9..d8eb67823df 100644
--- a/webapp/templates/jury/submission_source.html.twig
+++ b/webapp/templates/jury/submission_source.html.twig
@@ -68,7 +68,7 @@
                     </a>
                 </div>
 
-                {{ file.sourcecode | codeEditor(file.rank, submission.language.aceLanguage) }}
+                {{ file.content.sourcecode | codeEditor(file.rank, submission.language.aceLanguage) }}
             </div>
         {%- endfor %}
 
diff --git a/webapp/tests/Unit/Controller/API/SubmissionControllerTest.php b/webapp/tests/Unit/Controller/API/SubmissionControllerTest.php
index 9db4ca0b940..58aa287de80 100644
--- a/webapp/tests/Unit/Controller/API/SubmissionControllerTest.php
+++ b/webapp/tests/Unit/Controller/API/SubmissionControllerTest.php
@@ -308,7 +308,7 @@ public function testAddSuccess(
         $submissionFiles = [];
         /** @var SubmissionFile $file */
         foreach ($submission->getFiles() as $file) {
-            $submissionFiles[$file->getFilename()] = $file->getSourcecode();
+            $submissionFiles[$file->getFilename()] = $file->getContent()->getSourcecode();
         }
         static::assertEquals($expectedFiles, $submissionFiles, 'Wrong files');