diff --git a/device/common/include/traccc/finding/device/impl/make_barcode_sequence.ipp b/device/common/include/traccc/finding/device/impl/make_barcode_sequence.ipp
index c842edb2ef..0fe6b5d27e 100644
--- a/device/common/include/traccc/finding/device/impl/make_barcode_sequence.ipp
+++ b/device/common/include/traccc/finding/device/impl/make_barcode_sequence.ipp
@@ -1,12 +1,15 @@
 /** TRACCC library, part of the ACTS project (R&D line)
  *
- * (c) 2023 CERN for the benefit of the ACTS project
+ * (c) 2023-2024 CERN for the benefit of the ACTS project
  *
  * Mozilla Public License Version 2.0
  */
 
 #pragma once
 
+// System include(s).
+#include <cassert>
+
 namespace traccc::device {
 
 TRACCC_DEVICE inline void make_barcode_sequence(
@@ -16,8 +19,9 @@ TRACCC_DEVICE inline void make_barcode_sequence(
 
     measurement_collection_types::const_device uniques(uniques_view);
     vecmem::device_vector barcodes(barcodes_view);
+    assert(uniques.size() >= barcodes.size());
 
-    if (globalIndex >= uniques.size()) {
+    if (globalIndex >= barcodes.size()) {
         return;
     }