search for: lceplex_fr

...+=app_cepstral.so I assume that I put in here without the "#" or maybe "#" isn't a comment? Then.... and then after the section that compiles voicemail add app_cepstral.so: app_cepstral.c $(CC) -D_GNU_SOURCE -shared -Xlinker -x -o $@ $< -lz -lm -lceplex_uk -lceplex_fr -lswift -lceplex_us -lceplang_en -lceplang_fr -lz -ldl -L/opt/swift/lib -I/opt/swift/include Make sure the $(CC) line starts with a tab, not spaces. Note the example lines above only link against the uk, us and French libraries, if you use others then you'll need to link against those too/ins...