diff --git a/classes/search/PreprintSearch.php b/classes/search/PreprintSearch.php
index 75669d6b63..12491ed441 100644
--- a/classes/search/PreprintSearch.php
+++ b/classes/search/PreprintSearch.php
@@ -23,9 +23,7 @@
 use APP\core\Request;
 use APP\facades\Repo;
 use APP\server\Server;
-use PKP\controlledVocab\ControlledVocab;
 use PKP\db\DAORegistry;
-use PKP\facades\Locale;
 use PKP\plugins\Hook;
 use PKP\search\SubmissionSearch;
 use PKP\submission\PKPSubmission;
@@ -320,16 +318,16 @@ public function getSimilarityTerms($submissionId)
             $preprint = Repo::submission()->get($submissionId);
             if ($preprint->getData('status') === PKPSubmission::STATUS_PUBLISHED) {
                 // Retrieve keywords (if any).
-                $allSearchTerms = array_filter(
-                    Repo::controlledVocab()->getBySymbolic(
-                        ControlledVocab::CONTROLLED_VOCAB_SUBMISSION_KEYWORD,
-                        Application::ASSOC_TYPE_PUBLICATION,
-                        $preprint->getId(),
-                        [Locale::getLocale(), $preprint->getData('locale'), Locale::getPrimaryLocale()]
+                $allSearchTerms = collect($article->getCurrentPublication()->getData('keywords'))
+                    ->map(
+                        fn (array $items): array => collect($items)
+                            ->pluck('name')
+                            ->all()
                     )
-                );
+                    ->all();
+
                 foreach ($allSearchTerms as $locale => $localeSearchTerms) {
-                    $searchTerms += $localeSearchTerms;
+                    $searchTerms = array_merge($searchTerms, $localeSearchTerms);
                 }
             }
         }
diff --git a/classes/search/PreprintSearchIndex.php b/classes/search/PreprintSearchIndex.php
index eb9a1a53b6..31763139af 100644
--- a/classes/search/PreprintSearchIndex.php
+++ b/classes/search/PreprintSearchIndex.php
@@ -391,12 +391,16 @@ protected function _updateTextIndex($preprintId, $type, $text, $assocId = null)
     protected function _flattenLocalizedArray($arrayWithLocales)
     {
         $flattenedArray = [];
+
         foreach ($arrayWithLocales as $localeArray) {
-            $flattenedArray = array_merge(
-                $flattenedArray,
+            $names = array_map(
+                static fn ($item) => $item['name'],
                 $localeArray
             );
+
+            $flattenedArray = array_merge($flattenedArray, $names);
         }
+
         return $flattenedArray;
     }
 }
diff --git a/lib/pkp b/lib/pkp
index 3d0d78f292..9416a42243 160000
--- a/lib/pkp
+++ b/lib/pkp
@@ -1 +1 @@
-Subproject commit 3d0d78f292adc2d9e43d9f9f182fbaf5eec3cf9e
+Subproject commit 9416a42243274916a49f21ea7d0bd9b9fec44f43
diff --git a/plugins/metadata/dc11/filter/Dc11SchemaPreprintAdapter.php b/plugins/metadata/dc11/filter/Dc11SchemaPreprintAdapter.php
index d9235ba412..c335e63f11 100644
--- a/plugins/metadata/dc11/filter/Dc11SchemaPreprintAdapter.php
+++ b/plugins/metadata/dc11/filter/Dc11SchemaPreprintAdapter.php
@@ -26,7 +26,6 @@
 use APP\oai\ops\OAIDAO;
 use APP\plugins\PubIdPlugin;
 use APP\submission\Submission;
-use PKP\controlledVocab\ControlledVocab;
 use PKP\db\DAORegistry;
 use PKP\metadata\MetadataDataObjectAdapter;
 use PKP\metadata\MetadataDescription;
@@ -87,16 +86,20 @@ public function &extractMetadataFromDataObject(&$submission)
 
         // Subject
         $subjects = array_merge_recursive(
-            Repo::controlledVocab()->getBySymbolic(
-                ControlledVocab::CONTROLLED_VOCAB_SUBMISSION_KEYWORD,
-                Application::ASSOC_TYPE_PUBLICATION,
-                $publication->getId()
-            ),
-            Repo::controlledVocab()->getBySymbolic(
-                ControlledVocab::CONTROLLED_VOCAB_SUBMISSION_SUBJECT,
-                Application::ASSOC_TYPE_PUBLICATION,
-                $publication->getId()
-            )
+            collect($publication->getData('keywords'))
+                ->map(
+                    fn (array $items): array => collect($items)
+                        ->pluck('name')
+                        ->all()
+                )
+                ->all(),
+            collect($publication->getData('subjects'))
+                ->map(
+                    fn (array $items): array => collect($items)
+                        ->pluck('name')
+                        ->all()
+                )
+                ->all()
         );
         $this->_addLocalizedElements($dc11Description, 'dc:subject', $subjects);
 
diff --git a/plugins/oaiMetadataFormats/dc/tests/OAIMetadataFormat_DCTest.php b/plugins/oaiMetadataFormats/dc/tests/OAIMetadataFormat_DCTest.php
index 69c4ec2bd4..fae3d3cc3e 100755
--- a/plugins/oaiMetadataFormats/dc/tests/OAIMetadataFormat_DCTest.php
+++ b/plugins/oaiMetadataFormats/dc/tests/OAIMetadataFormat_DCTest.php
@@ -38,6 +38,7 @@
 use Mockery;
 use PHPUnit\Framework\Attributes\CoversClass;
 use PHPUnit\Framework\MockObject\MockObject;
+use PKP\controlledVocab\ControlledVocab;
 use PKP\controlledVocab\Repository as ControlledVocabRepository;
 use PKP\core\Dispatcher;
 use PKP\core\Registry;
@@ -96,6 +97,27 @@ public function testToXml()
         ]);
         $author->setEmail('someone@example.com');
 
+        /** @var ControlledVocabRepository|MockObject */
+        $controlledVocabRepoMock = Mockery::mock(ControlledVocabRepository::class)
+            ->makePartial()
+            ->shouldReceive('getBySymbolic')
+            ->twice()
+            ->andReturn(
+                [
+                    'en' => [
+                        ['name' => 'preprint-keyword'],
+                    ]
+                ],
+                [
+                    'en' => [
+                        ['name' => 'preprint-subject'],
+                        ['name' => 'preprint-subject-class'],
+                    ]
+                ]
+            )
+            ->getMock();
+        app()->instance(ControlledVocabRepository::class, $controlledVocabRepoMock);
+
         /** @var Publication|MockObject */
         $publication = $this->getMockBuilder(Publication::class)
             ->onlyMethods([])
@@ -113,6 +135,24 @@ public function testToXml()
         $publication->setData('copyrightYear', 'year');
         $publication->setData('datePublished', '2010-11-05');
         $publication->setData('authors', collect([$author]));
+        $publication->setData(
+            'keywords',
+            Repo::controlledVocab()->getBySymbolic(
+                ControlledVocab::CONTROLLED_VOCAB_SUBMISSION_KEYWORD,
+                0,
+                Application::ASSOC_TYPE_PUBLICATION
+            )['en'],
+            'en'
+        );
+        $publication->setData(
+            'subjects',
+            Repo::controlledVocab()->getBySymbolic(
+                ControlledVocab::CONTROLLED_VOCAB_SUBMISSION_SUBJECT,
+                0,
+                Application::ASSOC_TYPE_PUBLICATION
+            )['en'],
+            'en'
+        );
 
         // Preprint
         /** @var Submission|MockObject */
@@ -241,19 +281,6 @@ public function testToXml()
             ->willReturn(LazyCollection::wrap($galleys));
         app()->instance(GalleyCollector::class, $mockGalleyCollector);
 
-        $controlledVocabRepoMock = Mockery::mock(ControlledVocabRepository::class)
-            ->makePartial()
-            ->shouldReceive('getBySymbolic')
-            ->twice()
-            ->withAnyArgs()
-            ->andReturn(
-                ['en' => ['preprint-keyword']],
-                ['en' => ['preprint-subject', 'preprint-subject-class']]
-            )
-            ->getMock();
-
-        app()->instance(ControlledVocabRepository::class, $controlledVocabRepoMock);
-
         //
         // Test
         //
diff --git a/templates/frontend/objects/preprint_details.tpl b/templates/frontend/objects/preprint_details.tpl
index daa05717c1..01a2e05a87 100644
--- a/templates/frontend/objects/preprint_details.tpl
+++ b/templates/frontend/objects/preprint_details.tpl
@@ -183,7 +183,7 @@
 				</h2>
 				<span class="value">
 					{foreach name="keywords" from=$publication->getLocalizedData('keywords') item="keyword"}
-						{$keyword|escape}{if !$smarty.foreach.keywords.last}{translate key="common.commaListSeparator"}{/if}
+						{$keyword.name|escape}{if $keyword.identifier} ({$keyword.identifier|escape}){/if}{if !$smarty.foreach.keywords.last}{translate key="common.commaListSeparator"}{/if}
 					{/foreach}
 				</span>
 			</section>
diff --git a/templates/frontend/objects/preprint_summary.tpl b/templates/frontend/objects/preprint_summary.tpl
index 2d693b65ef..2f3a69cbd8 100644
--- a/templates/frontend/objects/preprint_summary.tpl
+++ b/templates/frontend/objects/preprint_summary.tpl
@@ -83,7 +83,7 @@
 		<div class="keywords">
 			<ul class="keyword_links">
 				{foreach name="keywords" from=$preprint->getCurrentPublication()->getLocalizedData('keywords') item="keyword"}
-					<li>{$keyword|escape}</li>
+					<li>{$keyword.name|escape}</li>
 				{/foreach}
 			</ul>
 		</div>