diff --git a/src/Storages/MergeTree/MergeTreeIndexHypothesisMergedCondition.cpp b/src/Storages/MergeTree/MergeTreeIndexHypothesisMergedCondition.cpp
index 6900ae1e69b..84195eb71b2 100644
--- a/src/Storages/MergeTree/MergeTreeIndexHypothesisMergedCondition.cpp
+++ b/src/Storages/MergeTree/MergeTreeIndexHypothesisMergedCondition.cpp
@@ -146,10 +146,15 @@ bool MergeTreeIndexhypothesisMergedCondition::mayBeTrueOnGranule(const MergeTree
         values.push_back(granule->met);
     }
 
-    if (const auto it = answer_cache.find(values); it != std::end(answer_cache))
-        return it->second;
+    const ComparisonGraph * graph = nullptr;
 
-    const auto & graph = getGraph(values);
+    {
+        std::lock_guard lock(cache_mutex);
+        if (const auto it = answer_cache.find(values); it != std::end(answer_cache))
+            return it->second;
+
+        graph = getGraph(values);
+    }
 
     bool always_false = false;
     expression_cnf->iterateGroups(
@@ -166,7 +171,7 @@ bool MergeTreeIndexhypothesisMergedCondition::mayBeTrueOnGranule(const MergeTree
                 if (func && func->arguments->children.size() == 2)
                 {
                     const auto expected = ComparisonGraph::atomToCompareResult(atom);
-                    if (graph.isPossibleCompare(expected, func->arguments->children[0], func->arguments->children[1]))
+                    if (graph->isPossibleCompare(expected, func->arguments->children[0], func->arguments->children[1]))
                     {
                         /// If graph failed use matching.
                         /// We don't need to check constraints.
@@ -177,6 +182,8 @@ bool MergeTreeIndexhypothesisMergedCondition::mayBeTrueOnGranule(const MergeTree
             always_false = true;
        });
 
+    std::lock_guard lock(cache_mutex);
+
     answer_cache[values] = !always_false;
     return !always_false;
 }
@@ -195,11 +202,13 @@ std::unique_ptr<ComparisonGraph> MergeTreeIndexhypothesisMergedCondition::buildG
     return std::make_unique<ComparisonGraph>(active_atomic_formulas);
 }
 
-const ComparisonGraph & MergeTreeIndexhypothesisMergedCondition::getGraph(const std::vector<bool> & values) const
+const ComparisonGraph * MergeTreeIndexhypothesisMergedCondition::getGraph(const std::vector<bool> & values) const
 {
-    if (!graph_cache.contains(values))
-        graph_cache[values] = buildGraph(values);
-    return *graph_cache.at(values);
+    auto [it, inserted] = graph_cache.try_emplace(values);
+    if (inserted)
+        it->second = buildGraph(values);
+
+    return it->second.get();
 }
 
 }
diff --git a/src/Storages/MergeTree/MergeTreeIndexHypothesisMergedCondition.h b/src/Storages/MergeTree/MergeTreeIndexHypothesisMergedCondition.h
index 530e14e15cc..9ebcbe9d7dc 100644
--- a/src/Storages/MergeTree/MergeTreeIndexHypothesisMergedCondition.h
+++ b/src/Storages/MergeTree/MergeTreeIndexHypothesisMergedCondition.h
@@ -21,11 +21,14 @@ public:
 private:
     void addConstraints(const ConstraintsDescription & constraints_description);
     std::unique_ptr<ComparisonGraph> buildGraph(const std::vector<bool> & values) const;
-    const ComparisonGraph & getGraph(const std::vector<bool> & values) const;
+    const ComparisonGraph * getGraph(const std::vector<bool> & values) const;
 
     ASTPtr expression_ast;
     std::unique_ptr<CNFQuery> expression_cnf;
 
+    /// Part analysis can be done in parallel.
+    /// So, we have shared answer and graph cache.
+    mutable std::mutex cache_mutex;
     mutable std::unordered_map<std::vector<bool>, std::unique_ptr<ComparisonGraph>> graph_cache;
     mutable std::unordered_map<std::vector<bool>, bool> answer_cache;
 
diff --git a/tests/queries/0_stateless/02150_index_hypothesis_race_long.reference b/tests/queries/0_stateless/02150_index_hypothesis_race_long.reference
new file mode 100644
index 00000000000..d86bac9de59
--- /dev/null
+++ b/tests/queries/0_stateless/02150_index_hypothesis_race_long.reference
@@ -0,0 +1 @@
+OK
diff --git a/tests/queries/0_stateless/02150_index_hypothesis_race_long.sh b/tests/queries/0_stateless/02150_index_hypothesis_race_long.sh
new file mode 100755
index 00000000000..da2dcd055ea
--- /dev/null
+++ b/tests/queries/0_stateless/02150_index_hypothesis_race_long.sh
@@ -0,0 +1,23 @@
+#!/usr/bin/env bash
+
+CURDIR=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
+# shellcheck source=../shell_config.sh
+. "$CURDIR"/../shell_config.sh
+
+$CLICKHOUSE_CLIENT -q "DROP TABLE IF EXISTS t_index_hypothesis"
+
+$CLICKHOUSE_CLIENT -q "CREATE TABLE t_index_hypothesis (a UInt32, b UInt32, INDEX t a != b TYPE hypothesis GRANULARITY 1) ENGINE = MergeTree ORDER BY a"
+
+$CLICKHOUSE_CLIENT -q "INSERT INTO t_index_hypothesis SELECT number, number + 1 FROM numbers(10000000)"
+
+for _ in {0..30}; do
+    output=`$CLICKHOUSE_CLIENT -q "SELECT count() FROM t_index_hypothesis WHERE a = b"`
+    if [[ $output != "0" ]]; then
+        echo "output: $output, expected: 0"
+        exit 1
+    fi
+done
+
+echo OK
+
+$CLICKHOUSE_CLIENT -q "DROP TABLE t_index_hypothesis"