diff --git a/src/lib/Server/Controller/Content/ContentVersionRelationDeleteController.php b/src/lib/Server/Controller/Content/ContentVersionRelationDeleteController.php
index 48fc56af3..648c1bd7e 100644
--- a/src/lib/Server/Controller/Content/ContentVersionRelationDeleteController.php
+++ b/src/lib/Server/Controller/Content/ContentVersionRelationDeleteController.php
@@ -11,6 +11,7 @@
 use ApiPlatform\OpenApi\Model;
 use Ibexa\Contracts\Core\Repository\ContentService;
 use Ibexa\Contracts\Core\Repository\Values\Content\Relation;
+use Ibexa\Contracts\Core\Repository\Values\Content\RelationType;
 use Ibexa\Contracts\Rest\Exceptions;
 use Ibexa\Rest\Server\Controller as RestController;
 use Ibexa\Rest\Server\Exceptions\ForbiddenException;
@@ -95,7 +96,7 @@ public function removeRelation(int $contentId, int $versionNumber, int $relation
 
         foreach ($versionRelations as $relation) {
             if ($relation->id == $relationId) {
-                if ($relation->type !== Relation::COMMON) {
+                if ($relation->type !== RelationType::COMMON->value) {
                     throw new ForbiddenException('Relation is not of type COMMON');
                 }
 
diff --git a/src/lib/Server/Output/ValueObjectVisitor/RestRelation.php b/src/lib/Server/Output/ValueObjectVisitor/RestRelation.php
index 724ac38f8..45b6980b6 100644
--- a/src/lib/Server/Output/ValueObjectVisitor/RestRelation.php
+++ b/src/lib/Server/Output/ValueObjectVisitor/RestRelation.php
@@ -7,7 +7,7 @@
 
 namespace Ibexa\Rest\Server\Output\ValueObjectVisitor;
 
-use Ibexa\Contracts\Core\Repository\Values\Content\Relation as RelationValue;
+use Ibexa\Contracts\Core\Repository\Values\Content\RelationType;
 use Ibexa\Contracts\Rest\Output\Generator;
 use Ibexa\Contracts\Rest\Output\ValueObjectVisitor;
 use Ibexa\Contracts\Rest\Output\Visitor;
@@ -92,19 +92,19 @@ protected function getRelationTypeString($relationType)
     {
         $relationTypeList = [];
 
-        if (RelationValue::COMMON & $relationType) {
+        if (RelationType::COMMON->value & $relationType) {
             $relationTypeList[] = 'COMMON';
         }
-        if (RelationValue::EMBED & $relationType) {
+        if (RelationType::EMBED->value & $relationType) {
             $relationTypeList[] = 'EMBED';
         }
-        if (RelationValue::LINK & $relationType) {
+        if (RelationType::LINK->value & $relationType) {
             $relationTypeList[] = 'LINK';
         }
-        if (RelationValue::FIELD & $relationType) {
+        if (RelationType::FIELD->value & $relationType) {
             $relationTypeList[] = 'ATTRIBUTE';
         }
-        if (RelationValue::ASSET & $relationType) {
+        if (RelationType::ASSET->value & $relationType) {
             $relationTypeList[] = 'ASSET';
         }