Hi Jochen, thanks for the response. I am using NEST 3.3 on Ubuntu 20.04.5 LTS which I installed from the command line (sudo apt-get install nest). However, when I build the nest-extension-module code it installs a fresh version of NEST from git (git clone https://github.com/nest/nest-simulator.git). I have followed the README from the extension module git (https://github.com/nest/nest-extension-module/). I cloned the repository to my local machine and then updated the CMakeLists.txt files in the outermost directory to have a unique short name for the module as well as read from the pif_psc_alpha.h file for the MODULE_HEADER. Finally, I updated the CMakeLists.txt in the src directory so that it only has one source (pif_psc_alpha.cpp pif_psc_alpha.h). These are the only changes that I make to the provided files. After this I run ./build.sh from the terminal, this installs the fresh NEST installation as mentioned above and it builds the .so files but errors on the installation. Let me know if I can provide any other details. Thanks!