diff --git a/wcfsetup/install/files/lib/data/TCollectionReactions.class.php b/wcfsetup/install/files/lib/data/TCollectionReactions.class.php
index 0bd62ed17d..2db706d714 100644
--- a/wcfsetup/install/files/lib/data/TCollectionReactions.class.php
+++ b/wcfsetup/install/files/lib/data/TCollectionReactions.class.php
@@ -41,7 +41,7 @@ private function loadReactionData(): void
         $this->reactionData = [];
 
         $objectType = ReactionHandler::getInstance()->getObjectType($this->getReactionObjectType());
-        ReactionHandler::getInstance()->loadLikeObjects($objectType, $this->getObjectIDs());
+        ReactionHandler::getInstance()->loadLikeObjects($objectType, $this->getObjectIDs(), false);
 
         foreach ($this->getObjectIDs() as $objectID) {
             $likeObject = ReactionHandler::getInstance()->getLikeObject($objectType, $objectID);
diff --git a/wcfsetup/install/files/lib/system/endpoint/controller/core/reactions/SetReaction.class.php b/wcfsetup/install/files/lib/system/endpoint/controller/core/reactions/SetReaction.class.php
index f7b5e963ee..377e44ed27 100644
--- a/wcfsetup/install/files/lib/system/endpoint/controller/core/reactions/SetReaction.class.php
+++ b/wcfsetup/install/files/lib/system/endpoint/controller/core/reactions/SetReaction.class.php
@@ -5,6 +5,7 @@
 use Laminas\Diactoros\Response\JsonResponse;
 use Psr\Http\Message\ResponseInterface;
 use Psr\Http\Message\ServerRequestInterface;
+use wcf\data\like\ILikeObjectTypeProvider;
 use wcf\data\like\IRestrictedLikeObjectTypeProvider;
 use wcf\data\like\Like;
 use wcf\data\like\object\ILikeObject;
@@ -49,6 +50,8 @@ public function __invoke(ServerRequestInterface $request, array $variables): Res
         }
 
         $objectTypeProvider = $objectType->getProcessor();
+        \assert($objectTypeProvider instanceof ILikeObjectTypeProvider);
+
         $likeable = $objectTypeProvider->getObjectByID($parameters->objectID);
         \assert($likeable instanceof ILikeObject);
         $likeable->setObjectType($objectType);
diff --git a/wcfsetup/install/files/lib/system/reaction/ReactionHandler.class.php b/wcfsetup/install/files/lib/system/reaction/ReactionHandler.class.php
index 11a97a3775..966cf6c4df 100644
--- a/wcfsetup/install/files/lib/system/reaction/ReactionHandler.class.php
+++ b/wcfsetup/install/files/lib/system/reaction/ReactionHandler.class.php
@@ -32,7 +32,7 @@
 final class ReactionHandler extends SingletonFactory
 {
     /**
-     * @var LikeObject[][]
+     * @var array<int, array<int, ?LikeObject>>
      */
     private array $likeObjectCache = [];
 
@@ -43,6 +43,7 @@ final class ReactionHandler extends SingletonFactory
 
     /**
      * @var ILikeObject[][]
+     * @deprecated 6.3
      */
     private array $likeableObjectsCache = [];
 
@@ -90,6 +91,8 @@ public function getReactionTypeByID(int $reactionID): ?ReactionType
 
     /**
      * Builds the data attributes for the object container.
+     *
+     * @deprecated 6.3
      */
     public function getDataAttributes(string $objectTypeName, int $objectID): string
     {
@@ -122,6 +125,8 @@ public function getDataAttributes(string $objectTypeName, int $objectID): string
 
     /**
      * @param list<int> $objectIDs
+     *
+     * @deprecated 6.3
      */
     public function cacheLikeableObjects(string $objectTypeName, array $objectIDs): void
     {
@@ -148,6 +153,8 @@ public function cacheLikeableObjects(string $objectTypeName, array $objectIDs):
 
     /**
      * Get an likeable object from the internal cache.
+     *
+     * @deprecated 6.3
      */
     public function getLikeableObject(string $objectTypeName, int $objectID): ILikeObject
     {
@@ -181,7 +188,10 @@ public function getObjectType(string $objectName): ?ObjectType
 
     public function getLikeObject(ObjectType $objectType, int $objectID): ?LikeObject
     {
-        if (!isset($this->likeObjectCache[$objectType->objectTypeID][$objectID])) {
+        if (
+            !isset($this->likeObjectCache[$objectType->objectTypeID])
+            || !\array_key_exists($objectID, $this->likeObjectCache[$objectType->objectTypeID])
+        ) {
             $this->loadLikeObjects($objectType, [$objectID]);
         }
 
@@ -196,7 +206,8 @@ public function getLikeObject(ObjectType $objectType, int $objectID): ?LikeObjec
     public function getLikeObjects(ObjectType $objectType): array
     {
         if (isset($this->likeObjectCache[$objectType->objectTypeID])) {
-            return $this->likeObjectCache[$objectType->objectTypeID];
+            // Use `array_filter` to filter `null` values.
+            return \array_filter($this->likeObjectCache[$objectType->objectTypeID]);
         }
 
         return [];
@@ -208,13 +219,15 @@ public function getLikeObjects(ObjectType $objectType): array
      *
      * @param list<int> $objectIDs
      */
-    public function loadLikeObjects(ObjectType $objectType, array $objectIDs): int
+    public function loadLikeObjects(ObjectType $objectType, array $objectIDs, bool $loadLikeableObjects = true): int
     {
         if (empty($objectIDs)) {
             return 0;
         }
 
-        $this->cacheLikeableObjects($objectType->objectType, $objectIDs);
+        if ($loadLikeableObjects) {
+            $this->cacheLikeableObjects($objectType->objectType, $objectIDs);
+        }
 
         $i = 0;
 
@@ -248,6 +261,10 @@ public function loadLikeObjects(ObjectType $objectType, array $objectIDs): int
             $i++;
         }
 
+        foreach ($objectIDs as $objectID) {
+            $this->likeObjectCache[$objectType->objectTypeID][$objectID] ??= null;
+        }
+
         return $i;
     }