diff --git a/configure.ac b/configure.ac
index 5e5a2c7..5971a4c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -33,8 +33,8 @@ AC_TYPE_UINT32_T
 AC_TYPE_UINT64_T
 AC_TYPE_INT32_T
 
-# --enable-debug support (default:no)
-AC_ARG_ENABLE([debug],AS_HELP_STRING([--enable-debug],[Debug flags]),[enable_debug=$enableval],[enable_debug="no"])
+# Debug support (default:no)
+AC_ARG_ENABLE([debug],AS_HELP_STRING([--enable-debug],[Enable debug output]),[enable_debug=$enableval],[enable_debug="no"])
  
 AC_MSG_CHECKING(for debug flag)
 AC_MSG_RESULT($enable_debug)
@@ -45,8 +45,8 @@ then
 fi
 AC_SUBST([DEBUG_CFLAGS])
 
-# --enable-serial-autoprobe support (default:yes)
-AC_ARG_ENABLE([serial-autoprobe],AS_HELP_STRING([--enable-serial-autoprobe],[Serial autoprobing flag]),[enable_serial_autoprobe=$enableval],[enable_serial_autoprobe="yes"])
+# Serial autoprobing support (default:yes)
+AC_ARG_ENABLE([serial-autoprobe],AS_HELP_STRING([--disable-serial-autoprobe],[Disable serial autoprobing]),[enable_serial_autoprobe=$enableval],[enable_serial_autoprobe="yes"])
  
 AC_MSG_CHECKING(for serial autoprobe flag)
 AC_MSG_RESULT($enable_serial_autoprobe)
@@ -56,8 +56,8 @@ then
   CFLAGS="$CFLAGS -DDISABLE_SERIAL_AUTOPROBE"
 fi
 
-# --enable-pcsc-lite support (default: yes)
-AC_ARG_ENABLE([pcsc-lite],AS_HELP_STRING([--enable-pcsc-lite],[pcsc-lite feature flag]),[enable_pcsc_lite=$enableval],[enable_pcsc_lite="yes"])
+# PCSC-lite support (default: yes)
+AC_ARG_ENABLE([pcsc-lite],AS_HELP_STRING([--disable-pcsc-lite],[Disable PCSC-lite dependency (removes ACR122 support)]),[enable_pcsc_lite=$enableval],[enable_pcsc_lite="yes"])
  
 AC_MSG_CHECKING(for pcsc-lite support)
 AC_MSG_RESULT($enable_pcsc_lite)
@@ -68,49 +68,62 @@ then
 fi
 AM_CONDITIONAL(PCSC_LITE_ENABLED, [test x"$enable_pcsc_lite" = xyes])
 
-## libusb
-if test x"$PKG_CONFIG" = "x"; then
-  AC_PATH_PROG(LIBUSB_CONFIG,libusb-config)
-  if test x"$LIBUSB_CONFIG" = "x" ; then
-    WITH_USB=0
-  else
-    LIBUSB_CFLAGS=`$LIBUSB_CONFIG --cflags`
-    LIBUSB_LIBS=`$LIBUSB_CONFIG --libs`
-    WITH_USB=1
-  fi
-else
-  PKG_CHECK_MODULES(LIBUSB, libusb, [WITH_USB=1], [WITH_USB=0])
+# libusb support (default: yes)
+AC_ARG_ENABLE([libusb],AS_HELP_STRING([--disable-libusb],[Disable libusb dependency (removes PN531USB and PN533USB support)]),[enable_libusb=$enableval],[enable_libusb="yes"])
+ 
+AC_MSG_CHECKING(for libusb support)
+AC_MSG_RESULT($enable_libusb)
+ 
+if test x"$enable_libsub" = "xno"
+then
+        WITH_LIBUSB=0
 fi
+AM_CONDITIONAL(LIBUSB_ENABLED, [test x"$enable_libusb" = xyes])
 
-if test x"$WITH_USB" = "x0"; then
-  AC_MSG_ERROR([libusb is mandatory.])
+## libusb
+if test "x$enable_libusb" = "xyes"; then
+  if test x"$PKG_CONFIG" = "x"; then
+    AC_PATH_PROG(LIBUSB_CONFIG,libusb-config)
+    if test x"$LIBUSB_CONFIG" = "x" ; then
+      WITH_USB=0
+    else
+      LIBUSB_CFLAGS=`$LIBUSB_CONFIG --cflags`
+      LIBUSB_LIBS=`$LIBUSB_CONFIG --libs`
+      WITH_USB=1
+    fi
+  else
+    PKG_CHECK_MODULES(LIBUSB, libusb, [WITH_USB=1], [WITH_USB=0])
+  fi
+  
+  if test x"$WITH_USB" = "x0"; then
+    AC_MSG_ERROR([libusb is mandatory.])
+  fi
+  AC_SUBST(LIBUSB_LIBS)
+  AC_SUBST(LIBUSB_CFLAGS)
 fi
-AC_SUBST(LIBUSB_LIBS)
-AC_SUBST(LIBUSB_CFLAGS)
 
 ## libpcsclite
-if test "x$enable_pcsc_lite" = "xyes"
-then
-case "$host" in
-  *darwin*)
-    AC_MSG_WARN(Using darwin PCSC Framework)
-    LIBPCSCLITE_LIBS="-Wl,-framework,PCSC"
-    LIBPCSCLITE_CFLAGS="-I/System/Library/Frameworks/PCSC.framework/Headers"
-  ;;
-  *)
-    PKG_CHECK_MODULES(LIBPCSCLITE, libpcsclite, [WITH_PCSC=1], [WITH_PCSC=0])
-    if test x"$WITH_PCSC" = "x0" ; then
-      AC_MSG_ERROR([libpcsclite is mandatory.])
-    fi
-  ;;
-esac
+if test "x$enable_pcsc_lite" = "xyes"; then
+  case "$host" in
+    *darwin*)
+      AC_MSG_WARN(Using darwin PCSC Framework)
+      LIBPCSCLITE_LIBS="-Wl,-framework,PCSC"
+      LIBPCSCLITE_CFLAGS="-I/System/Library/Frameworks/PCSC.framework/Headers"
+    ;;
+    *)
+      PKG_CHECK_MODULES(LIBPCSCLITE, libpcsclite, [WITH_PCSC=1], [WITH_PCSC=0])
+      if test x"$WITH_PCSC" = "x0" ; then
+        AC_MSG_ERROR([libpcsclite is mandatory.])
+      fi
+    ;;
+  esac
   AC_SUBST(LIBPCSCLITE_LIBS)
   AC_SUBST(LIBPCSCLITE_CFLAGS)
 fi
 
 # Set C standard to C99
-# --disable-std-c99 support (default: no)
-AC_ARG_ENABLE([std-c99],AS_HELP_STRING([--disable-pcsc-lite],[compile using C99 standard]),[enable_std_c99=$enableval],[enable_std_c99="yes"])
+# C99 standard support (default: yes)
+AC_ARG_ENABLE([std-c99],AS_HELP_STRING([--disable-std-c99],[Disable C99 standard when compiling]),[enable_std_c99=$enableval],[enable_std_c99="yes"])
  
 AC_MSG_CHECKING(for C99 support)
 AC_MSG_RESULT($enable_std_c99)
diff --git a/src/Makefile.am b/src/Makefile.am
index 93a0099..47a50bf 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -5,7 +5,7 @@ bin_PROGRAMS = nfc-anticol nfc-list nfc-mftool nfc-mfultool nfc-relay nfc-emulat
 # set the include path found by configure
 INCLUDES= $(all_includes)
 
-nfc_devices_headers = dev_arygon.h dev_pn531.h dev_pn533.h
+nfc_devices_headers = dev_arygon.h
 nfc_examples_headers = mifaretag.h mifareultag.h
 nfcinclude_HEADERS = libnfc.h bitutils.h defines.h types.h rs232.h devices.h messages.h
 nfcinclude_HEADERS += $(nfc_devices_headers)
@@ -13,9 +13,9 @@ nfcinclude_HEADERS += $(nfc_examples_headers)
 nfcincludedir = $(includedir)/libnfc
 
 lib_LTLIBRARIES = libnfc.la
-libnfc_la_SOURCES = bitutils.c libnfc.c rs232.c dev_arygon.c dev_pn531.c dev_pn533.c
-libnfc_la_CFLAGS = @LIBUSB_CFLAGS@
-libnfc_la_LIBADD = @LIBUSB_LIBS@
+libnfc_la_SOURCES = bitutils.c libnfc.c rs232.c dev_arygon.c
+libnfc_la_CFLAGS = 
+libnfc_la_LIBADD = 
 
 if PCSC_LITE_ENABLED
   nfcinclude_HEADERS += dev_acr122.h
@@ -24,6 +24,13 @@ if PCSC_LITE_ENABLED
   libnfc_la_LIBADD += @LIBPCSCLITE_LIBS@
 endif
 
+if LIBUSB_ENABLED
+  nfcinclude_HEADERS += dev_pn531.h dev_pn533.h
+  libnfc_la_CFLAGS += @LIBUSB_CFLAGS@ -DHAVE_LIBUSB
+  libnfc_la_SOURCES += dev_pn531.c dev_pn533.c
+  libnfc_la_LIBADD  += @LIBUSB_LIBS@
+endif
+
 nfc_anticol_SOURCES = anticol.c
 nfc_anticol_LDADD = libnfc.la