--- configure.ac.orig	2013-02-07 17:24:02.000000000 +0100
+++ configure.ac	2013-02-07 17:26:53.000000000 +0100
@@ -879,14 +879,14 @@
 if test $build_ft2232_ftd2xx = yes -o $build_presto_ftd2xx = yes ; then
    AC_MSG_CHECKING([for libftd2xx.a (darwin)])
 
-   if test ! -f /usr/local/include/ftd2xx.h ; then
-      AC_MSG_ERROR([ftd2xx library from FTDICHIP.com seems to be missing, cannot find: /usr/local/include/ftd2xx.h])
+   if test ! -f $prefix/include/ftd2xx.h ; then
+      AC_MSG_ERROR([ftd2xx library from FTDICHIP.com seems to be missing, cannot find: $prefix/include/ftd2xx.h])
    fi
 
-   CFLAGS="$CFLAGS -I/usr/local/include"
-   LDFLAGS="$LDFLAGS -L/usr/local/lib"
+   CFLAGS="$CFLAGS -I$prefix/include"
+   LDFLAGS="$LDFLAGS -L$prefix/lib"
    LIBS="$LIBS -lftd2xx"
-   AC_MSG_RESULT([-L/usr/local/lib -lftd2xx])
+   AC_MSG_RESULT([-L$prefix/lib -lftd2xx])
 fi
 fi # darwin
 
--- configure.orig	2013-02-07 17:29:21.000000000 +0100
+++ configure	2013-02-07 17:29:40.000000000 +0100
@@ -14186,15 +14186,15 @@
    { $as_echo "$as_me:${as_lineno-$LINENO}: checking for libftd2xx.a (darwin)" >&5
 $as_echo_n "checking for libftd2xx.a (darwin)... " >&6; }
 
-   if test ! -f /usr/local/include/ftd2xx.h ; then
-      as_fn_error $? "ftd2xx library from FTDICHIP.com seems to be missing, cannot find: /usr/local/include/ftd2xx.h" "$LINENO" 5
+   if test ! -f $prefix/include/ftd2xx.h ; then
+      as_fn_error $? "ftd2xx library from FTDICHIP.com seems to be missing, cannot find: $prefix/include/ftd2xx.h" "$LINENO" 5
    fi
 
-   CFLAGS="$CFLAGS -I/usr/local/include"
-   LDFLAGS="$LDFLAGS -L/usr/local/lib"
+   CFLAGS="$CFLAGS -I$prefix/include"
+   LDFLAGS="$LDFLAGS -L$prefix/lib"
    LIBS="$LIBS -lftd2xx"
-   { $as_echo "$as_me:${as_lineno-$LINENO}: result: -L/usr/local/lib -lftd2xx" >&5
-$as_echo "-L/usr/local/lib -lftd2xx" >&6; }
+   { $as_echo "$as_me:${as_lineno-$LINENO}: result: -L$prefix/lib -lftd2xx" >&5
+$as_echo "-L$prefix/lib -lftd2xx" >&6; }
 fi
 fi # darwin