diff --git a/.vscode/settings.json b/.vscode/settings.json
index 8044b1c..e375c2a 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -2,6 +2,7 @@
     "files.associations": {
         "string": "cpp",
         "vector": "cpp",
-        "deque": "cpp"
+        "deque": "cpp",
+        "ostream": "cpp"
     }
 }
\ No newline at end of file
diff --git a/lib/mysql.hpp b/lib/mysql.hpp
index 26b2674..762007d 100644
--- a/lib/mysql.hpp
+++ b/lib/mysql.hpp
@@ -5,6 +5,7 @@
 #include <vector>
 #include <map>
 #include <iostream>
+#include <mutex>
 
 #include <mysql_driver.h>
 #include <mysql_connection.h>
@@ -22,7 +23,7 @@ using namespace mysql;
 
 class mySQL {
     public:
-
+    mutex io;
     MySQL_Driver *drv;
     Connection *con;
     string path, username, password, db;
diff --git a/src/mysql.cpp b/src/mysql.cpp
index 01b1243..80f7da3 100644
--- a/src/mysql.cpp
+++ b/src/mysql.cpp
@@ -22,21 +22,24 @@ mySQL::mySQL(const string _path, const string _username, const string _password,
 }
 
 bool mySQL::open(const string _db) {
+   io.lock();
    db = _db.empty() ? db : _db;
    bool status = true;
 
    try {
       con->setSchema(db);
       status = false;
+      io.unlock();
    }
    catch (const SQLException &error) {
       cout << error.what() << endl;
+      io.unlock();
    } 
-
    return status;
 }
 
 bool mySQL::connect() {
+   io.lock();
    uint trys = 0;
    bool status = true;
 
@@ -45,10 +48,12 @@ bool mySQL::connect() {
          drv = get_mysql_driver_instance();
          con = drv->connect(path, username, password);
          status = false;
+         io.unlock();
       }
       catch (const SQLException &error) {
          cout << error.what() << endl;
          usleep(10000*trys++);
+         io.unlock();
       }
    }
 
@@ -56,15 +61,18 @@ bool mySQL::connect() {
 }
 
 bool mySQL::close() {
+   io.lock();
    bool status = true;
 
    if (con->isValid() && !con->isClosed()) {
       try {
          con->close();
          status = false;
+         io.unlock();
       } 
       catch (const SQLException &error) {
          cout << error.what() << endl;
+         io.unlock();
       }
    }
 
@@ -83,6 +91,7 @@ map<string, vector<string>> mySQL::query(const string sql_command) {
       }
    }
 
+   io.lock();
    /**/
    map<string, vector<string>> maped;
 
@@ -115,12 +124,15 @@ map<string, vector<string>> mySQL::query(const string sql_command) {
       delete res;
       delete stmt;
 
+      io.unlock();
    }
    catch (const SQLException &error) {
       cout << error.what() << endl;
+      io.unlock();
    }
    catch (const string error) {
       throw error;
+      io.unlock();
    }
 
    /**/
@@ -146,6 +158,7 @@ bool mySQL::change(const string sql_command) {
       }
    }
 
+   io.lock();
    /**/
    bool status = false;
    
@@ -157,13 +170,15 @@ bool mySQL::change(const string sql_command) {
       status = (bool)changeCatch;
 
       delete stmt;
-
+      io.unlock();
    }
    catch (const SQLException &error) {
       cout << error.what() << endl;
+      io.unlock();
    }
    catch (const string error) {
       throw error;
+      io.unlock();
    }
 
    /**/
diff --git a/test/test.cpp b/test/test.cpp
index 77c162d..70bec39 100644
--- a/test/test.cpp
+++ b/test/test.cpp
@@ -10,7 +10,7 @@ int main() {
 
     try {
 
-        auto res = mydb.query("SELECT * FROM users");
+        auto res = mydb.query("SELECT * FROM records");
 
         for (auto i : res) {
             for (auto j: i.second) {
@@ -18,9 +18,9 @@ int main() {
             }
         }
 
-        if (mydb.change("UPDATE records SET enabled = 0 WHERE domain = 'bitelex.ml'")) {
-            cout << "Update sucessfuly" << endl;
-        }
+        // if (mydb.change("UPDATE records SET enabled = 0 WHERE domain = 'bitelex.ml'")) {
+        //     cout << "Update sucessfuly" << endl;
+        // }
 
     }
     catch (const SQLException error) {
diff --git a/test/test.o b/test/test.o
index 6958657..81818ce 100755
Binary files a/test/test.o and b/test/test.o differ