diff --git a/src/AggregateFunctions/AggregateFunctionIf.h b/src/AggregateFunctions/AggregateFunctionIf.h
index 47f04dad9a4..cd7d7e27a25 100644
--- a/src/AggregateFunctions/AggregateFunctionIf.h
+++ b/src/AggregateFunctions/AggregateFunctionIf.h
@@ -152,6 +152,13 @@ public:
         nested_func->merge(place, rhs, arena);
     }
 
+    bool isAbleToParallelizeMerge() const override { return nested_func->isAbleToParallelizeMerge(); }
+
+    void merge(AggregateDataPtr __restrict place, ConstAggregateDataPtr rhs, ThreadPool & thread_pool, Arena * arena) const override
+    {
+        nested_func->merge(place, rhs, thread_pool, arena);
+    }
+
     void mergeBatch(
         size_t row_begin,
         size_t row_end,
diff --git a/tests/performance/uniqExactIf.xml b/tests/performance/uniqExactIf.xml
new file mode 100644
index 00000000000..24899660177
--- /dev/null
+++ b/tests/performance/uniqExactIf.xml
@@ -0,0 +1,3 @@
+<test>
+    <query>SELECT uniqExactIf(number, ) FROM numbers_mt(1e7)</query>
+</test>