diff --git a/app/Repositories/Summit/DoctrineSpeakerRepository.php b/app/Repositories/Summit/DoctrineSpeakerRepository.php
index 237042028..2a5dd6c41 100644
--- a/app/Repositories/Summit/DoctrineSpeakerRepository.php
+++ b/app/Repositories/Summit/DoctrineSpeakerRepository.php
@@ -705,23 +705,22 @@ function ($query) {
      */
     public function getUniqueActivitiesCountBySummit(Summit $summit, Filter $filter = null): int
     {
-        // Inner query: distinct IDs of speakers who belong to this summit (via assignment
-        // or moderator role) and match any caller-supplied filter. Uses IDENTITY() with a
-        // scalar summit ID so no entity parameter is embedded in the getDQL() string —
-        // entity parameters copied into an outer QB via getDQL() are not correctly resolved
-        // to their primary key by Doctrine's type system.
+        // Build the EXISTS inner QB rooted at PresentationSpeaker (e) with the joins that
+        // filter mappings expect (m, rr). The initial WHERE ties e to the outer presentation
+        // p via assignment or moderator role; filter conditions are then appended by
+        // apply2Query.  The EXISTS approach lets MySQL use the
+        // index on Presentation_Speakers(PresentationID) to reach speakers for each p directly
+        // and short-circuit on the first match.
         $innerQb = $this->getEntityManager()->createQueryBuilder()
-            ->select('e.id')
-            ->distinct(true)
+            ->select('1')
             ->from('models\summit\PresentationSpeaker', 'e')
-            ->leftJoin('e.registration_request', 'rr')
             ->leftJoin('e.member', 'm')
+            ->leftJoin('e.registration_request', 'rr')
             ->where(
                 'EXISTS (SELECT 1 FROM App\Models\Foundation\Summit\Speakers\PresentationSpeakerAssignment __a'
-                . ' JOIN __a.presentation __ap WHERE IDENTITY(__ap.summit) = :summit_id AND __a.speaker = e)'
-                . ' OR EXISTS (SELECT 1 FROM models\summit\Presentation __mp WHERE IDENTITY(__mp.summit) = :summit_id AND __mp.moderator = e)'
-            )
-            ->setParameter('summit_id', $summit->getId());
+                . ' WHERE __a.presentation = p AND __a.speaker = e)'
+                . ' OR p.moderator = e'
+            );
 
         if (!is_null($filter)) {
             $filter->apply2Query($innerQb, $this->getFilterMappings($filter));
@@ -729,30 +728,22 @@ public function getUniqueActivitiesCountBySummit(Summit $summit, Filter $filter
 
         $innerDql = $innerQb->getDQL();
 
-        // Outer query counts distinct presentations where at least one matched speaker is
-        // either an assigned speaker or the moderator. The inner DQL is embedded exactly
-        // once (inside a single wrapper EXISTS) to avoid Doctrine alias-conflict errors.
-        $outerQb = $this->getEntityManager()->createQueryBuilder()
+        $qb = $this->getEntityManager()->createQueryBuilder()
             ->select('COUNT(DISTINCT p.id)')
             ->from('models\summit\Presentation', 'p')
             ->where('p.summit = :summit')
-            ->andWhere(
-                'EXISTS ('
-                . 'SELECT 1 FROM models\summit\PresentationSpeaker __spk'
-                . ' WHERE __spk.id IN (' . $innerDql . ')'
-                . ' AND ('
-                . 'EXISTS (SELECT 1 FROM App\Models\Foundation\Summit\Speakers\PresentationSpeakerAssignment __cnt WHERE __cnt.presentation = p AND __cnt.speaker = __spk)'
-                . ' OR p.moderator = __spk'
-                . ')'
-                . ')'
-            )
+            ->andWhere('EXISTS (' . $innerDql . ')')
             ->setParameter('summit', $summit);
 
+        // Copy filter-specific parameter bindings (e.g. :value_N for text/id filters).
+        // Filter sub-queries reference :summit by name; that is satisfied by the binding above.
         foreach ($innerQb->getParameters() as $param) {
-            $outerQb->setParameter($param->getName(), $param->getValue());
+            if ($param->getName() !== 'summit') {
+                $qb->setParameter($param->getName(), $param->getValue(), $param->getType());
+            }
         }
 
-        return intval($outerQb->getQuery()->getSingleScalarResult());
+        return intval($qb->getQuery()->getSingleScalarResult());
     }
 
     /**