diff --git a/webapp/src/Controller/API/AbstractApiController.php b/webapp/src/Controller/API/AbstractApiController.php
index 163f000bba..b5c43a76d9 100644
--- a/webapp/src/Controller/API/AbstractApiController.php
+++ b/webapp/src/Controller/API/AbstractApiController.php
@@ -34,9 +34,11 @@ public function __construct(
      * Get the query builder used for getting contests.
      *
      * @param bool $onlyActive return only contests that are active
+     * @param bool $filterBeforeContest return only contests that have started
      */
-    protected function getContestQueryBuilder(bool $onlyActive = false): QueryBuilder
-    {
+    protected function getContestQueryBuilder(
+        bool $onlyActive = false, bool $filterBeforeContest = true
+    ): QueryBuilder {
         $now = Utils::now();
         $qb = $this->em->createQueryBuilder();
         $qb
@@ -63,6 +65,10 @@ protected function getContestQueryBuilder(bool $onlyActive = false): QueryBuilde
             } else {
                 $qb->andWhere('c.public = 1');
             }
+            if ($filterBeforeContest) {
+                $qb->andWhere('c.starttime <= :now')
+                   ->setParameter('now', $now);
+            }
         }
 
         return $qb;
@@ -77,7 +83,10 @@ protected function getContestId(Request $request): int
             throw new BadRequestHttpException('cid parameter missing');
         }
 
-        $qb = $this->getContestQueryBuilder($request->query->getBoolean('onlyActive', false));
+        $qb = $this->getContestQueryBuilder(
+                onlyActive: $request->query->getBoolean('onlyActive', false),
+                filterBeforeContest: false
+        );
         $qb
             ->andWhere(sprintf('c.%s = :cid', $this->getContestIdField()))
             ->setParameter('cid', $request->attributes->get('cid'));
diff --git a/webapp/src/Controller/API/ContestController.php b/webapp/src/Controller/API/ContestController.php
index 317d49cdcb..b0f4ce8ceb 100644
--- a/webapp/src/Controller/API/ContestController.php
+++ b/webapp/src/Controller/API/ContestController.php
@@ -179,7 +179,7 @@ public function singleAction(Request $request, string $cid): Response
     public function bannerAction(Request $request, string $cid): Response
     {
         /** @var Contest|null $contest */
-        $contest = $this->getQueryBuilder($request)
+        $contest = $this->getQueryBuilder($request, filterBeforeContest: false)
             ->andWhere(sprintf('%s = :id', $this->getIdField()))
             ->setParameter('id', $cid)
             ->getQuery()
@@ -934,10 +934,10 @@ public function samplesDataZipAction(Request $request): Response
         return $this->dj->getSamplesZipForContest($contest);
     }
 
-    protected function getQueryBuilder(Request $request): QueryBuilder
+    protected function getQueryBuilder(Request $request, bool $filterBeforeContest = true): QueryBuilder
     {
         try {
-            return $this->getContestQueryBuilder($request->query->getBoolean('onlyActive', false));
+            return $this->getContestQueryBuilder($request->query->getBoolean('onlyActive', false), $filterBeforeContest);
         } catch (TypeError) {
             throw new BadRequestHttpException('\'onlyActive\' must be a boolean.');
         }
@@ -954,7 +954,7 @@ protected function getIdField(): string
      */
     protected function getContestWithId(Request $request, string $id): Contest
     {
-        $queryBuilder = $this->getQueryBuilder($request)
+        $queryBuilder = $this->getQueryBuilder($request, filterBeforeContest: false)
             ->andWhere(sprintf('%s = :id', $this->getIdField()))
             ->setParameter('id', $id);
 
@@ -971,7 +971,7 @@ protected function getContestWithId(Request $request, string $id): Contest
     private function getContestAndCheckIfLocked(Request $request, string $cid): Contest
     {
         /** @var Contest|null $contest */
-        $contest = $this->getQueryBuilder($request)
+        $contest = $this->getQueryBuilder($request, filterBeforeContest: false)
             ->andWhere(sprintf('%s = :id', $this->getIdField()))
             ->setParameter('id', $cid)
             ->getQuery()