Gson not able to serialize map with equal sign correctly

Question

I have a Java Hashmap as follows:

map.put("targetStatus","2");
map.put("targetAvailable","Availability=false")

I am using Gson library to convert the map into Json :

Gson gson = new Gson();
String jsonString = gson.toJson(map);

Output

{
"map": {
 "targetStatus": "2",
  "targetAvailable": "Availability\u003dfalse"
  }
}

Could someone help me out, why is the = sign not displayed when converted to json. Thanks in advance!