--- a/configure.ac
+++ b/configure.ac
@@ -59,9 +59,10 @@
 MD_CHECK_OS
 
 MD_CHECK_LIBUSB018B
+LIBS="$LIBS $LIBUSB_LIBS"
+INCLUDES="$INCLUDES $LIBUSB_CFLAGS"
 
 AC_PROG_CC
-MD_CHECK_GCC3
 
 dnl MD_CONF_DISTCC
 dnl MD_CONF_CCACHE
@@ -78,7 +79,6 @@
 AC_C_BIGENDIAN
 AC_C_STRINGIZE
 
-MD_CONF_DEBUGGING
 MD_CONF_COMPILER
 AM_CONDITIONAL(OS_LINUX, test "$MD_OS" = "linux")
 AM_CONDITIONAL(OS_BSD, test "$MD_OS" = "bsd")
@@ -98,13 +98,6 @@
 
 MD_CHECK_DOXYGEN
 
-MD_CONF_FLAGS(
-  [],
-  [$OS_CFLAGS $LIBUSB_CFLAGS],
-  [],
-  [$OS_LDFLAGS $LIBUSB_LIBS]
-)
-
 MD_CONF_DB2MAN
 
 ##### OUTPUT #################################################################