diff -ur gsmlib-1.10/gsmlib/gsm_unix_serial.cc gsmlib-1.10-fixed/gsmlib/gsm_unix_serial.cc
--- gsmlib-1.10/gsmlib/gsm_unix_serial.cc	2002-09-22 23:51:10.000000000 +1200
+++ gsmlib-1.10-fixed/gsmlib/gsm_unix_serial.cc	2004-06-24 18:07:16.776486024 +1200
@@ -26,6 +26,7 @@
 #include <sys/ioctl.h>
 #include <signal.h>
 #include <pthread.h>
+#include <cassert>
 
 using namespace std;
 using namespace gsmlib;