diff --git a/dbms/include/DB/AggregateFunctions/AggregateFunctionGroupArray.h b/dbms/include/DB/AggregateFunctions/AggregateFunctionGroupArray.h
index 987c20a4bef..5b9428af0b2 100644
--- a/dbms/include/DB/AggregateFunctions/AggregateFunctionGroupArray.h
+++ b/dbms/include/DB/AggregateFunctions/AggregateFunctionGroupArray.h
@@ -47,7 +47,7 @@ public:
 
 	void merge(AggregateDataPtr place, ConstAggregateDataPtr rhs) const
 	{
-		data(place).value.insert(data(place).value.begin(), data(rhs).value.begin(), data(rhs).value.end());
+		data(place).value.insert(data(place).value.end(), data(rhs).value.begin(), data(rhs).value.end());
 	}
 
 	void serialize(ConstAggregateDataPtr place, WriteBuffer & buf) const
diff --git a/dbms/tests/queries/0_stateless/00113_group_array.reference b/dbms/tests/queries/0_stateless/00113_group_array.reference
new file mode 100644
index 00000000000..2b501e8d65a
--- /dev/null
+++ b/dbms/tests/queries/0_stateless/00113_group_array.reference
@@ -0,0 +1,12 @@
+0	100
+1	100
+2	100
+3	100
+4	100
+5	100
+6	100
+7	100
+8	100
+9	100
+
+0	1000000
diff --git a/dbms/tests/queries/0_stateless/00113_group_array.sql b/dbms/tests/queries/0_stateless/00113_group_array.sql
new file mode 100644
index 00000000000..e9c2d0956ec
--- /dev/null
+++ b/dbms/tests/queries/0_stateless/00113_group_array.sql
@@ -0,0 +1 @@
+SELECT intDiv(number, 100) AS k, length(groupArray(number)) FROM (SELECT * FROM system.numbers LIMIT 1000000) GROUP BY k WITH TOTALS ORDER BY k LIMIT 10;