diff --git a/castor-service/src/main/java/io/carbynestack/castor/service/persistence/fragmentstore/TupleChunkFragmentRepository.java b/castor-service/src/main/java/io/carbynestack/castor/service/persistence/fragmentstore/TupleChunkFragmentRepository.java
index 8b26f94..00ca34f 100644
--- a/castor-service/src/main/java/io/carbynestack/castor/service/persistence/fragmentstore/TupleChunkFragmentRepository.java
+++ b/castor-service/src/main/java/io/carbynestack/castor/service/persistence/fragmentstore/TupleChunkFragmentRepository.java
@@ -388,10 +388,12 @@ ArrayList<TupleChunkFragmentEntity> lockAndRetrieveReservedTuplesForConsumption(
               + TUPLE_CHUNK_ID_COLUMN
               + " = :tupleChunkId AND "
               + START_INDEX_COLUMN
-              + " = :startIdx RETURNING "
+              + " <= :startIdx AND "
+              + END_INDEX_COLUMN
+              + " > :startIdx RETURNING "
               + RESERVATION_ID_COLUMN,
       nativeQuery = true)
-  String lockFirstTupleReturningReservatioId(
+  String lockFirstFragmentReturningReservationId(
       @Param("tupleChunkId") UUID tupleChunkId, @Param("startIdx") long startIdx);
 
   @Transactional
diff --git a/castor-service/src/main/java/io/carbynestack/castor/service/persistence/fragmentstore/TupleChunkFragmentStorageService.java b/castor-service/src/main/java/io/carbynestack/castor/service/persistence/fragmentstore/TupleChunkFragmentStorageService.java
index 9e9b326..6576424 100644
--- a/castor-service/src/main/java/io/carbynestack/castor/service/persistence/fragmentstore/TupleChunkFragmentStorageService.java
+++ b/castor-service/src/main/java/io/carbynestack/castor/service/persistence/fragmentstore/TupleChunkFragmentStorageService.java
@@ -132,7 +132,7 @@ public ArrayList<TupleChunkFragmentEntity> lockReservedFragments(String reservat
   public int lockReservedFragmentsWithoutRetrieving(
       UUID tupleChunkId, long startIdx, String reservationId) {
     String deletedId =
-        fragmentRepository.lockFirstTupleReturningReservatioId(tupleChunkId, startIdx);
+        fragmentRepository.lockFirstFragmentReturningReservationId(tupleChunkId, startIdx);
     if (deletedId != null && deletedId.equals(reservationId))
       return 1 + fragmentRepository.lockRemainingTuplesWithoutRetrieving(reservationId);
     else
diff --git a/castor-service/src/test/java/io/carbynestack/castor/service/persistence/cache/ReservationCachingServiceIT.java b/castor-service/src/test/java/io/carbynestack/castor/service/persistence/cache/ReservationCachingServiceIT.java
index 192d3ac..2eda690 100644
--- a/castor-service/src/test/java/io/carbynestack/castor/service/persistence/cache/ReservationCachingServiceIT.java
+++ b/castor-service/src/test/java/io/carbynestack/castor/service/persistence/cache/ReservationCachingServiceIT.java
@@ -225,7 +225,7 @@ void testComposing() {
     Answer mocklockFirstTupleReturningReservationId =
         (Answer)
             invocation -> {
-              return tupleChunkFragmentRepository.lockFirstTupleReturningReservatioId(
+              return tupleChunkFragmentRepository.lockFirstFragmentReturningReservationId(
                   invocation.getArgument(0, UUID.class), invocation.getArgument(1, Long.class));
             };