S2695 : NPE when sql query is defined in other file than the file currently analyzed

package sonar.testcase;

import java.sql.Connection;
import java.sql.PreparedStatement;

public class ExtendedClass extends BaseClass {

    protected void prepareReport(Connection connection) throws Exception {
        try {
            String sql = SQL_QUERY_BASE;
            PreparedStatement pstmt = connection.prepareStatement(sql);
            pstmt.setString(1, "smth"); 
        } catch (Exception e) {}
    }
}

package sonar.testcase;

public class BaseClass {
    public static final String SQL_QUERY_BASE = "select * from MYTABLE where customerId = ?"; // Declaration can not be retrieved when analyzing ExtendedClass.java
}