diff --git a/src/Columns/ColumnAggregateFunction.cpp b/src/Columns/ColumnAggregateFunction.cpp
index e26fe790a8e..4bc48c62eb4 100644
--- a/src/Columns/ColumnAggregateFunction.cpp
+++ b/src/Columns/ColumnAggregateFunction.cpp
@@ -330,7 +330,38 @@ ColumnPtr ColumnAggregateFunction::filter(const Filter & filter, ssize_t result_
 
 void ColumnAggregateFunction::expand(const Filter & mask, bool inverted)
 {
-    expandDataByMask<char *>(data, mask, inverted);
+    ensureOwnership();
+    Arena & arena = createOrGetArena();
+
+    if (mask.size() < data.size())
+        throw Exception(ErrorCodes::LOGICAL_ERROR, "Mask size should be no less than data size.");
+
+    ssize_t from = data.size() - 1;
+    ssize_t index = mask.size() - 1;
+    data.resize(mask.size());
+    while (index >= 0)
+    {
+        if (!!mask[index] ^ inverted)
+        {
+            if (from < 0)
+                throw Exception(ErrorCodes::LOGICAL_ERROR, "Too many bytes in mask");
+
+            /// Copy only if it makes sense.
+            if (index != from)
+                data[index] = data[from];
+            --from;
+        }
+        else
+        {
+            data[index] = arena.alignedAlloc(func->sizeOfData(), func->alignOfData());
+            func->create(data[index]);
+        }
+
+        --index;
+    }
+
+    if (from != -1)
+        throw Exception(ErrorCodes::LOGICAL_ERROR, "Not enough bytes in mask");
 }
 
 ColumnPtr ColumnAggregateFunction::permute(const Permutation & perm, size_t limit) const
diff --git a/tests/queries/0_stateless/03210_variant_with_aggregate_function_type.reference b/tests/queries/0_stateless/03210_variant_with_aggregate_function_type.reference
new file mode 100644
index 00000000000..105e8e7d8bd
--- /dev/null
+++ b/tests/queries/0_stateless/03210_variant_with_aggregate_function_type.reference
@@ -0,0 +1,6 @@
+	500
+fail	500
+	499
+fail	500
+	500	499
+fail	500	500
diff --git a/tests/queries/0_stateless/03210_variant_with_aggregate_function_type.sql b/tests/queries/0_stateless/03210_variant_with_aggregate_function_type.sql
new file mode 100644
index 00000000000..cb9cdb0b456
--- /dev/null
+++ b/tests/queries/0_stateless/03210_variant_with_aggregate_function_type.sql
@@ -0,0 +1,60 @@
+SET allow_experimental_variant_type = 1;
+
+DROP TABLE IF EXISTS source;
+CREATE TABLE source 
+(
+   Name String,
+   Value Int64
+
+) ENGINE = MergeTree ORDER BY ();
+
+INSERT INTO source SELECT ['fail', 'success'][number % 2] as Name, number AS Value FROM numbers(1000);
+
+DROP TABLE IF EXISTS test_agg_variant;
+CREATE TABLE test_agg_variant
+(
+   Name String,
+   Value Variant(AggregateFunction(uniqExact, Int64), AggregateFunction(avg, Int64))
+)
+ENGINE = MergeTree
+ORDER BY (Name);
+
+INSERT INTO test_agg_variant
+SELECT
+    Name,
+    t AS Value
+FROM
+(
+    SELECT
+        Name,
+        arrayJoin([
+            uniqExactState(Value)::Variant(AggregateFunction(uniqExact, Int64), AggregateFunction(avg, Int64)), 
+            avgState(Value)::Variant(AggregateFunction(uniqExact, Int64), AggregateFunction(avg, Int64))
+        ]) AS t
+    FROM source
+    GROUP BY Name 
+);
+
+SELECT
+    Name,
+    uniqExactMerge(Value.`AggregateFunction(uniqExact, Int64)`) AS Value
+FROM test_agg_variant
+GROUP BY Name;
+
+SELECT
+    Name,
+    avgMerge(Value.`AggregateFunction(avg, Int64)`) AS Value
+FROM test_agg_variant
+GROUP BY Name;
+
+SELECT
+    Name,
+    uniqExactMerge(Value.`AggregateFunction(uniqExact, Int64)`) AS ValueUniq,
+    avgMerge(Value.`AggregateFunction(avg, Int64)`) AS ValueAvg
+FROM test_agg_variant
+GROUP BY Name;
+
+
+DROP TABLE test_agg_variant;
+DROP TABLE source;
+