diff --git a/dbms/src/Common/HashTable/HashTable.h b/dbms/src/Common/HashTable/HashTable.h
index dadc73c3f44..ade51969bea 100644
--- a/dbms/src/Common/HashTable/HashTable.h
+++ b/dbms/src/Common/HashTable/HashTable.h
@@ -224,8 +224,18 @@ private:
 
 public:
     bool hasZero() const { return has_zero; }
-    void setHasZero() { has_zero = true; }
-    void clearHasZero() { has_zero = false; }
+
+    void setHasZero()
+    {
+        has_zero = true;
+        new (zeroValue()) Cell();
+    }
+
+    void clearHasZero()
+    {
+        has_zero = false;
+        zeroValue()->~Cell();
+    }
 
     Cell * zeroValue()             { return reinterpret_cast<Cell*>(&zero_value_storage); }
     const Cell * zeroValue() const { return reinterpret_cast<const Cell*>(&zero_value_storage); }
diff --git a/dbms/tests/queries/0_stateless/01011_group_uniq_array_memsan.reference b/dbms/tests/queries/0_stateless/01011_group_uniq_array_memsan.reference
new file mode 100644
index 00000000000..b7c55c59479
--- /dev/null
+++ b/dbms/tests/queries/0_stateless/01011_group_uniq_array_memsan.reference
@@ -0,0 +1 @@
+[[],[2]]
diff --git a/dbms/tests/queries/0_stateless/01011_group_uniq_array_memsan.sql b/dbms/tests/queries/0_stateless/01011_group_uniq_array_memsan.sql
new file mode 100644
index 00000000000..b8c16e48c42
--- /dev/null
+++ b/dbms/tests/queries/0_stateless/01011_group_uniq_array_memsan.sql
@@ -0,0 +1 @@
+select groupUniqArray(v) from values('id int, v Array(int)', (1, [2]), (1, [])) group by id;