sim808.h library has errors

i have bought sim808 with leonardo mainboard . I followed the steps given and tried the gsm programs, but there is an error given by the arduino IDE. please help. Here is the error ...


In file included from C:\Program Files (x86)\Arduino\libraries\SIM808\src/sim808ModemCore.h:5:0,
from C:\Program Files (x86)\Arduino\libraries\SIM808\src/sim808AccessProvider.h:5,
from C:\Program Files (x86)\Arduino\libraries\SIM808\src/sim808.h:3,
from SendSMS.ino:25:
C:\Program Files (x86)\Arduino\libraries\SIM808\src/sim808BaseProvider.h:37:33: error: 'prog_char' has not been declared
void prepareAuxLocate(PROGMEM prog_char str[], char auxLocate[]);
^
In file included from C:\Program Files (x86)\Arduino\libraries\SIM808\src/sim808AccessProvider.h:5:0,
from C:\Program Files (x86)\Arduino\libraries\SIM808\src/sim808.h:3,
from SendSMS.ino:25:
C:\Program Files (x86)\Arduino\libraries\SIM808\src/sim808ModemCore.h:66:35: error: 'prog_char' has not been declared
virtual size_t writePGM(PROGMEM prog_char str[], bool CR = true);
^
C:\Program Files (x86)\Arduino\libraries\SIM808\src/sim808ModemCore.h:70:34: error: 'prog_char' has not been declared
void genericCommand_rq(PROGMEM prog_char str[], bool addCR = true);//Generates a generic AT command request from PROGMEM prog_char buffer
^
Error compiling.