diff --git a/src/DataTypes/Serializations/SerializationMap.cpp b/src/DataTypes/Serializations/SerializationMap.cpp
index fa882bef7ca..ff8bc518dc0 100644
--- a/src/DataTypes/Serializations/SerializationMap.cpp
+++ b/src/DataTypes/Serializations/SerializationMap.cpp
@@ -80,8 +80,13 @@ void SerializationMap::deserializeBinary(IColumn & column, ReadBuffer & istr) co
 }
 
 
-template <typename Writer>
-void SerializationMap::serializeTextImpl(const IColumn & column, size_t row_num, bool quote_key, WriteBuffer & ostr, Writer && writer) const
+template <typename KeyWriter, typename ValueWriter>
+void SerializationMap::serializeTextImpl(
+    const IColumn & column,
+    size_t row_num,
+    WriteBuffer & ostr,
+    KeyWriter && key_writer,
+    ValueWriter && value_writer) const
 {
     const auto & column_map = assert_cast<const ColumnMap &>(column);
 
@@ -98,17 +103,9 @@ void SerializationMap::serializeTextImpl(const IColumn & column, size_t row_num,
         if (i != offset)
             writeChar(',', ostr);
 
-        if (quote_key)
-        {
-            writeChar('"', ostr);
-            writer(key, nested_tuple.getColumn(0), i);
-            writeChar('"', ostr);
-        }
-        else
-            writer(key, nested_tuple.getColumn(0), i);
-
+        key_writer(key, nested_tuple.getColumn(0), i);
         writeChar(':', ostr);
-        writer(value, nested_tuple.getColumn(1), i);
+        value_writer(value, nested_tuple.getColumn(1), i);
     }
     writeChar('}', ostr);
 }
@@ -170,11 +167,12 @@ void SerializationMap::deserializeTextImpl(IColumn & column, ReadBuffer & istr,
 
 void SerializationMap::serializeText(const IColumn & column, size_t row_num, WriteBuffer & ostr, const FormatSettings & settings) const
 {
-    serializeTextImpl(column, row_num, /*quote_key=*/ false, ostr,
-        [&](const SerializationPtr & subcolumn_serialization, const IColumn & subcolumn, size_t pos)
-        {
-            subcolumn_serialization->serializeTextQuoted(subcolumn, pos, ostr, settings);
-        });
+    auto writer = [&](const SerializationPtr & subcolumn_serialization, const IColumn & subcolumn, size_t pos)
+    {
+        subcolumn_serialization->serializeTextQuoted(subcolumn, pos, ostr, settings);
+    };
+
+    serializeTextImpl(column, row_num, ostr, writer, writer);
 }
 
 void SerializationMap::deserializeText(IColumn & column, ReadBuffer & istr, const FormatSettings & settings) const
@@ -188,11 +186,14 @@ void SerializationMap::deserializeText(IColumn & column, ReadBuffer & istr, cons
 
 void SerializationMap::serializeTextJSON(const IColumn & column, size_t row_num, WriteBuffer & ostr, const FormatSettings & settings) const
 {
-    /// We need to double-quote integer keys to produce valid JSON.
-    const auto & column_key = assert_cast<const ColumnMap &>(column).getNestedData().getColumn(0);
-    bool quote_key = !WhichDataType(column_key.getDataType()).isStringOrFixedString();
-
-    serializeTextImpl(column, row_num, quote_key, ostr,
+    serializeTextImpl(column, row_num, ostr,
+        [&](const SerializationPtr & subcolumn_serialization, const IColumn & subcolumn, size_t pos)
+        {
+            /// We need to double-quote all keys (including integers) to produce valid JSON.
+            WriteBufferFromOwnString str_buf;
+            subcolumn_serialization->serializeText(subcolumn, pos, str_buf, settings);
+            writeJSONString(str_buf.str(), ostr, settings);
+        },
         [&](const SerializationPtr & subcolumn_serialization, const IColumn & subcolumn, size_t pos)
         {
             subcolumn_serialization->serializeTextJSON(subcolumn, pos, ostr, settings);
diff --git a/src/DataTypes/Serializations/SerializationMap.h b/src/DataTypes/Serializations/SerializationMap.h
index bf68689f1e4..6523d5388d0 100644
--- a/src/DataTypes/Serializations/SerializationMap.h
+++ b/src/DataTypes/Serializations/SerializationMap.h
@@ -60,8 +60,8 @@ public:
         SubstreamsCache * cache) const override;
 
 private:
-    template <typename Writer>
-    void serializeTextImpl(const IColumn & column, size_t row_num, bool quote_key, WriteBuffer & ostr, Writer && writer) const;
+    template <typename KeyWriter, typename ValueWriter>
+    void serializeTextImpl(const IColumn & column, size_t row_num, WriteBuffer & ostr, KeyWriter && key_writer, ValueWriter && value_writer) const;
 
     template <typename Reader>
     void deserializeTextImpl(IColumn & column, ReadBuffer & istr, Reader && reader) const;
diff --git a/tests/queries/0_stateless/01939_type_map_json.reference b/tests/queries/0_stateless/01939_type_map_json.reference
index 9b831c29608..4c19bc3c0dc 100644
--- a/tests/queries/0_stateless/01939_type_map_json.reference
+++ b/tests/queries/0_stateless/01939_type_map_json.reference
@@ -4,5 +4,11 @@
 {'key1':1,'key2':2}	{"key1":"1","key2":"2"}	1
 {"m":{"key1":1,"key2":2}}
 {'key1':1,'key2':2}	{"key1":1,"key2":2}	1
-{"m1":{"k1":"1","k2":"2"},"m2":{"1":2,"2":3}}
-{"m1":{"k1":1,"k2":2},"m2":{"1":2,"2":3}}
+{"m":{"2020-10-10":"v1","2020-10-11":"v2"}}
+{'2020-10-10':'v1','2020-10-11':'v2'}	{"2020-10-10":"v1","2020-10-11":"v2"}	1
+{"m":{"11":"v1","22":"v2"}}
+{11:'v1',22:'v2'}	{"11":"v1","22":"v2"}	1
+{"m":{"11":"v1","22":"v2"}}
+{11:'v1',22:'v2'}	{"11":"v1","22":"v2"}	1
+{"m1":{"k1":"1","k2":"2"},"m2":{"1":2,"2":3},"m3":{"2020-10-10":"foo"}}
+{"m1":{"k1":1,"k2":2},"m2":{"1":2,"2":3},"m3":{"2020-10-10":"foo"}}
diff --git a/tests/queries/0_stateless/01939_type_map_json.sql b/tests/queries/0_stateless/01939_type_map_json.sql
index 4ad25f3c073..df782334c90 100644
--- a/tests/queries/0_stateless/01939_type_map_json.sql
+++ b/tests/queries/0_stateless/01939_type_map_json.sql
@@ -11,9 +11,18 @@ SELECT map('key1', number, 'key2', number * 2) AS m FROM numbers(1, 1)
 SELECT map('key1', number, 'key2', number * 2) AS m, toJSONString(m) AS s, isValidJSON(s) FROM numbers(1, 1)
     SETTINGS output_format_json_quote_64bit_integers = 0;
 
-CREATE TEMPORARY TABLE map_json (m1 Map(String, UInt64), m2 Map(UInt32, UInt32));
+SELECT map('2020-10-10'::Date, 'v1', '2020-10-11'::Date, 'v2') AS m FORMAT JSONEachRow;
+SELECT map('2020-10-10'::Date, 'v1', '2020-10-11'::Date, 'v2') AS m, toJSONString(m) AS s, isValidJSON(s);
 
-INSERT INTO map_json FORMAT JSONEachRow {"m1" : {"k1" : 1, "k2" : 2}, "m2" : {"1" : 2, "2" : 3}};
+SELECT map(11::UInt64, 'v1', 22::UInt64, 'v2') AS m FORMAT JSONEachRow;
+SELECT map(11::UInt64, 'v1', 22::UInt64, 'v2') AS m, toJSONString(m) AS s, isValidJSON(s);
 
-SELECT m1, m2 FROM map_json FORMAT JSONEachRow;
-SELECT m1, m2 FROM map_json FORMAT JSONEachRow SETTINGS output_format_json_quote_64bit_integers = 0;
+SELECT map(11::Int128, 'v1', 22::Int128, 'v2') AS m FORMAT JSONEachRow;
+SELECT map(11::Int128, 'v1', 22::Int128, 'v2') AS m, toJSONString(m) AS s, isValidJSON(s);
+
+CREATE TEMPORARY TABLE map_json (m1 Map(String, UInt64), m2 Map(UInt32, UInt32), m3 Map(Date, String));
+
+INSERT INTO map_json FORMAT JSONEachRow {"m1" : {"k1" : 1, "k2" : 2}, "m2" : {"1" : 2, "2" : 3}, "m3" : {"2020-10-10" : "foo"}};
+
+SELECT m1, m2, m3 FROM map_json FORMAT JSONEachRow;
+SELECT m1, m2, m3 FROM map_json FORMAT JSONEachRow SETTINGS output_format_json_quote_64bit_integers = 0;