diff --git a/src/Columns/ReverseIndex.h b/src/Columns/ReverseIndex.h
index 9f13dbef1f9..1f49e2cb225 100644
--- a/src/Columns/ReverseIndex.h
+++ b/src/Columns/ReverseIndex.h
@@ -317,7 +317,7 @@ class ReverseIndex
 {
 public:
     ReverseIndex(UInt64 num_prefix_rows_to_skip_, UInt64 base_index_)
-        : num_prefix_rows_to_skip(num_prefix_rows_to_skip_), base_index(base_index_), saved_hash_ptr(nullptr) {}
+        : num_prefix_rows_to_skip(num_prefix_rows_to_skip_), base_index(base_index_), external_saved_hash_ptr(nullptr) {}
 
     void setColumn(ColumnType * column_);
 
@@ -352,14 +352,14 @@ public:
         if (!use_saved_hash)
             return nullptr;
 
-        UInt64 * ptr = saved_hash_ptr.load();
+        UInt64 * ptr = external_saved_hash_ptr.load();
         if (!ptr)
         {
             auto hash = calcHashes();
             ptr = &hash->getData()[0];
             UInt64 * expected = nullptr;
-            if (saved_hash_ptr.compare_exchange_strong(expected, ptr))
-                saved_hash = std::move(hash);
+            if (external_saved_hash_ptr.compare_exchange_strong(expected, ptr))
+                external_saved_hash = std::move(hash);
             else
                 ptr = expected;
         }
@@ -379,7 +379,9 @@ private:
     /// Lazy initialized.
     std::unique_ptr<IndexMapType> index;
     mutable ColumnUInt64::MutablePtr saved_hash;
-    mutable std::atomic<UInt64 *> saved_hash_ptr;
+    /// For usage during GROUP BY
+    mutable ColumnUInt64::MutablePtr external_saved_hash;
+    mutable std::atomic<UInt64 *> external_saved_hash_ptr;
 
     void buildIndex();
 
diff --git a/tests/queries/0_stateless/02046_low_cardinality_parallel_group_by.reference b/tests/queries/0_stateless/02046_low_cardinality_parallel_group_by.reference
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/tests/queries/0_stateless/02046_low_cardinality_parallel_group_by.sh b/tests/queries/0_stateless/02046_low_cardinality_parallel_group_by.sh
new file mode 100755
index 00000000000..ec58f36cede
--- /dev/null
+++ b/tests/queries/0_stateless/02046_low_cardinality_parallel_group_by.sh
@@ -0,0 +1,22 @@
+#!/usr/bin/env bash
+
+CURDIR=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
+# shellcheck source=../shell_config.sh
+. "$CURDIR"/../shell_config.sh
+
+# This is the regression test for parallel usage of LowCardinality column
+# via Buffer engine.
+#
+# See also:
+# - https://github.com/ClickHouse/ClickHouse/issues/24158
+# - https://github.com/ClickHouse/ClickHouse/pull/3138
+
+$CLICKHOUSE_CLIENT -q "DROP TABLE IF EXISTS low_card_buffer_test"
+$CLICKHOUSE_CLIENT -q "CREATE TABLE low_card_buffer_test (test_text LowCardinality(String)) ENGINE=Buffer('', '', 16, 60, 360, 100, 1000, 10000, 100000)"
+
+$CLICKHOUSE_BENCHMARK -d 0 -i 1000 -c 5 <<<"SELECT count() FROM low_card_buffer_test GROUP BY test_text format Null" 2>/dev/null &
+$CLICKHOUSE_BENCHMARK -d 0 -i 1000 -c 2 <<<"INSERT INTO low_card_buffer_test values('TEST1')" 2>/dev/null &
+wait
+
+# server is alive
+$CLICKHOUSE_CLIENT -q "SELECT 1 FORMAT Null"