--- configure.ac.orig	2008-09-16 15:11:28.000000000 +0200
+++ configure.ac	2008-09-16 15:10:12.000000000 +0200
@@ -206,6 +206,18 @@
 AC_CHECK_SIZEOF(void*)
 
 AC_ARG_ENABLE(
+    [backtrace],
+    AC_HELP_STRING([--enable-backtrace],[enable the usage of backtrace (default auto)]),
+    [ac_enable_backtrace=$enableleval],
+    [ac_enable_backtrace=auto]
+)
+AC_ARG_ENABLE(
+    [ucontexth],
+    AC_HELP_STRING([--enable-ucontexth],[enable the usage of ucontext.h (default auto)]),
+    [ac_enable_ucontexth=$enableleval],
+    [ac_enable_ucontexth=auto]
+)
+AC_ARG_ENABLE(
 	[asm],
 	AC_HELP_STRING([--enable-asm],[enable the Pentium assembler optimizations (default auto)]),
 	[ac_enable_asm=$enableval],
@@ -320,7 +332,10 @@
 	AC_HEADER_TIOCGWINSZ
 	AC_CHECK_HEADERS([unistd.h sched.h netdb.h termios.h execinfo.h])
 	AC_CHECK_HEADERS([sys/utsname.h sys/types.h sys/stat.h sys/socket.h sys/select.h sys/ioctl.h sys/time.h sys/mman.h sys/io.h sys/kd.h sys/vt.h])
-	AC_CHECK_HEADERS([netinet/in.h ucontext.h])
+	AC_CHECK_HEADERS([netinet/in.h])
+    if test $ac_enable_ucontexth = auto; then
+    	AC_CHECK_HEADERS([ucontext.h])
+    fi
 	AC_C_CONST
 	AC_C_RESTRICT
 	AC_C_INLINE
@@ -329,7 +344,10 @@
 	AC_FUNC_SELECT_ARGTYPES
 	AC_FUNC_VPRINTF
 	AC_CHECK_FUNCS([strcasecmp strerror])
-	AC_CHECK_FUNCS([uname sysconf backtrace backtrace_symbols])
+    if test $ac_enable_backtrace = auto; then
+        AC_CHECK_FUNCS([backtrace backtrace_symbols])
+    fi
+	AC_CHECK_FUNCS([uname sysconf])
 	AC_CHECK_FUNCS([flockfile funlockfile fread_unlocked fwrite_unlocked fgetc_unlocked feof_unlocked])
 	AC_CHECK_FUNCS([iopl mprotect])
 	AC_MSG_CHECKING([for port in/out])