diff --git a/src/lib/models/Event.ts b/src/lib/models/Event.ts
index c52e9a1..d6564d6 100644
--- a/src/lib/models/Event.ts
+++ b/src/lib/models/Event.ts
@@ -68,7 +68,11 @@ export class Event extends Model<Event> {
      */
     public async joined({userId}: {userId: number}, request: any): Promise<boolean> {
         userId = userId ?? request.session.userId;
-        const participants = await this.$get("rParticipants", {where: {id: userId}}) as User[];
-        return participants.length !== 0;
+        if (userId) {
+            const participants = await this.$get("rParticipants", {where: {id: userId}}) as User[];
+            return participants.length !== 0;
+        } else {
+            return false;
+        }
     }
 }
diff --git a/src/lib/models/Group.ts b/src/lib/models/Group.ts
index f7f7ce0..f4f83a8 100644
--- a/src/lib/models/Group.ts
+++ b/src/lib/models/Group.ts
@@ -129,7 +129,11 @@ export class Group extends Model<Group> {
      */
     public async joined({userId}: {userId: number}, request: any): Promise<boolean> {
         userId = userId ?? request.session.userId;
-        const members = await this.$get("rMembers", {where: {id: userId}}) as User[];
-        return members.length !== 0;
+        if (userId) {
+            const members = await this.$get("rMembers", {where: {id: userId}}) as User[];
+            return members.length !== 0;
+        } else {
+            return false;
+        }
     }
 }
diff --git a/src/lib/models/Post.ts b/src/lib/models/Post.ts
index 59ee1de..af67f06 100644
--- a/src/lib/models/Post.ts
+++ b/src/lib/models/Post.ts
@@ -137,8 +137,12 @@ export class Post extends Model<Post> {
      */
     public async userVote({userId}: {userId: number}, request: any): Promise<VoteType> {
         userId = userId ?? request.session.userId;
-        const votes = await this.$get("rVotes", {where: {id: userId}}) as Array<User & {PostVote: PostVote}>;
-        return votes[0]?.PostVote?.voteType;
+        if (userId) {
+            const votes = await this.$get("rVotes", {where: {id: userId}}) as Array<User & {PostVote: PostVote}>;
+            return votes[0]?.PostVote?.voteType;
+        } else {
+            return undefined;
+        }
     }
 
     /**
@@ -149,7 +153,7 @@ export class Post extends Model<Post> {
     public async deletable({userId}: {userId: number}, request: any): Promise<boolean> {
         userId = userId ?? request.session.userId;
         const isAuthor =  Number(userId) === Number(this.authorId);
-        if (!isAuthor) {
+        if (userId && !isAuthor) {
             return (await User.findOne({where: {id: userId}})).isAdmin;
         }
         return isAuthor;