diff --git a/src/app/api/event/[eventID]/route.ts b/src/app/api/event/[eventID]/route.ts
index 8c06b64..123685b 100644
--- a/src/app/api/event/[eventID]/route.ts
+++ b/src/app/api/event/[eventID]/route.ts
@@ -229,23 +229,6 @@ export const PATCH = auth(async (req, { params }) => {
     participants,
   } = data.data;
 
-  if (participants !== undefined)
-    for (const participant of participants) {
-      await prisma.meetingParticipant.upsert({
-        where: {
-          meeting_id_user_id: {
-            user_id: participant,
-            meeting_id: eventID,
-          },
-        },
-        create: {
-          user_id: participant,
-          meeting_id: eventID,
-        },
-        update: {},
-      });
-    }
-
   const updatedEvent = await prisma.meeting.update({
     where: {
       id: eventID,
@@ -257,16 +240,18 @@ export const PATCH = auth(async (req, { params }) => {
       end_time,
       location,
       status,
-      participants:
-        participants !== undefined
-          ? {
-              deleteMany: {
-                user_id: {
-                  notIn: participants || [],
-                },
-              },
-            }
-          : {},
+      participants: !participants
+        ? undefined
+        : {
+          deleteMany: {
+            user_id: {
+              notIn: participants,
+            },
+          },
+            create: participants.map((participant) => ({
+              user_id: participant,
+            })),
+          },
     },
     select: {
       id: true,
diff --git a/src/app/api/event/validation.ts b/src/app/api/event/validation.ts
index b8e176b..da5912f 100644
--- a/src/app/api/event/validation.ts
+++ b/src/app/api/event/validation.ts
@@ -113,6 +113,7 @@ export const createEventSchema = zod
 // ----------------------------------------
 export const updateEventSchema = zod
   .object({
+    id: eventIdSchema,
     title: eventTitleSchema.optional(),
     description: eventDescriptionSchema.optional(),
     start_time: eventStartTimeSchema.optional(),