Conflict between Arduino GSM and SoftwareSerial

Hello everyone,

I just learned that there would be a conflict between the GSM and SoftwareSerial libraries, because the GSM would have its own version of SoftwareSerial.
I turn to you to see if there is a solution to this, without using AltSoftSerial because it would make me see a lot of things, given the complexity of my programs.

Here is my compilation error :

GSM\GSM3SoftSerial.cpp.o: In function `__vector_9':
C:\Elec\Arduino\arduino-1.6.5\libraries\GSM\src/GSM3SoftSerial.cpp:499: multiple definition of `__vector_9'
SoftwareSerial\SoftwareSerial.cpp.o:C:\Elec\Arduino\arduino-1.6.5\hardware\arduino\avr\libraries\SoftwareSerial/SoftwareSerial.cpp:227: first defined here
c:/elec/arduino/arduino-1.6.5/hardware/tools/avr/bin/../lib/gcc/avr/4.8.1/../../../../avr/bin/ld.exe: Disabling relaxation: it will not work with multiple definitions
GSM\GSM3SoftSerial.cpp.o: In function `GSM3SoftSerial::spaceAvailable()':
C:\Elec\Arduino\arduino-1.6.5\libraries\GSM\src/GSM3SoftSerial.cpp:487: multiple definition of `__vector_10'
SoftwareSerial\SoftwareSerial.cpp.o:C:\Elec\Arduino\arduino-1.6.5\hardware\arduino\avr\libraries\SoftwareSerial/SoftwareSerial.cpp:392: first defined here
GSM\GSM3SoftSerial.cpp.o: In function `GSM3SoftSerial::spaceAvailable()':
C:\Elec\Arduino\arduino-1.6.5\libraries\GSM\src/GSM3SoftSerial.cpp:487: multiple definition of `__vector_11'
SoftwareSerial\SoftwareSerial.cpp.o:C:\Elec\Arduino\arduino-1.6.5\hardware\arduino\avr\libraries\SoftwareSerial/SoftwareSerial.cpp:392: first defined here
collect2.exe: error: ld returned 1 exit status
Erreur lors de la compilation.

Well, if anyone could help me, I would be grateful!