diff --git a/internal/core/src/cachinglayer/CacheSlot.h b/internal/core/src/cachinglayer/CacheSlot.h
index 2097b9c9ea..b7a9f4db99 100644
--- a/internal/core/src/cachinglayer/CacheSlot.h
+++ b/internal/core/src/cachinglayer/CacheSlot.h
@@ -19,7 +19,6 @@
 #include <utility>
 #include <vector>
 
-#include <flat_hash_map/flat_hash_map.hpp>
 #include <folly/futures/Future.h>
 #include <folly/futures/SharedPromise.h>
 #include <folly/Synchronized.h>
@@ -111,7 +110,7 @@ class CacheSlot final : public std::enable_shared_from_this<CacheSlot<CellT>> {
                                                       -> std::shared_ptr<
                                                           CellAccessor<CellT>> {
             auto count = std::min(uids.size(), cells_.size());
-            ska::flat_hash_set<cid_t> involved_cids;
+            std::unordered_set<cid_t> involved_cids;
             involved_cids.reserve(count);
             switch (cell_id_mapping_mode_) {
                 case CellIdMappingMode::IDENTICAL: {