diff --git a/code/api/api/src/main/java/com/decathlon/ara/ci/service/ExecutionIndexerService.java b/code/api/api/src/main/java/com/decathlon/ara/ci/service/ExecutionIndexerService.java
index 2b875dde..2bbf7847 100644
--- a/code/api/api/src/main/java/com/decathlon/ara/ci/service/ExecutionIndexerService.java
+++ b/code/api/api/src/main/java/com/decathlon/ara/ci/service/ExecutionIndexerService.java
@@ -34,10 +34,7 @@
 import org.springframework.transaction.annotation.Transactional;
 
 import java.io.File;
-import java.util.Collections;
-import java.util.List;
-import java.util.Optional;
-import java.util.Set;
+import java.util.*;
 import java.util.stream.Collectors;
 
 @Service
@@ -116,7 +113,8 @@ public void indexExecution(PlannedIndexation plannedIndexation) {
 
         final Execution savedExecution = executionRepository.save(processedExecution.get());
 
-        List<Long> newErrorIds = getErrorIds(Optional.of(savedExecution));
+        List<Long> newErrorIds = new ArrayList<>(getErrorIds(Optional.of(savedExecution)));
+
         newErrorIds.removeAll(existingErrorIds);
         if (!newErrorIds.isEmpty()) {
             final Set<Problem> updatedProblems = errorService.autoAssignProblemsToNewErrors(projectId, newErrorIds);