diff --git a/src/server/api/client/[clientId]/enable.post.ts b/src/server/api/client/[clientId]/enable.post.ts
index 406c33ac..16f2fbb8 100644
--- a/src/server/api/client/[clientId]/enable.post.ts
+++ b/src/server/api/client/[clientId]/enable.post.ts
@@ -12,6 +12,19 @@ export default definePermissionEventHandler(
     const client = await Database.clients.get(clientId);
     checkPermissions(client);
 
+    if (
+      client &&
+      client.expiresAt !== null &&
+      new Date() > new Date(client.expiresAt)
+    ) {
+      throw createError({
+        statusCode: 422,
+        statusMessage:
+          'Client is expired. Please update the expiration date first.',
+        message: 'Client is expired. Please update the expiration date first.',
+      });
+    }
+
     await Database.clients.toggle(clientId, true);
     await WireGuard.saveConfig();
     return { success: true };