diff --git a/Makefile.am b/Makefile.am
index 175d63b8..cd83ef48 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -542,8 +542,7 @@ else
 build_plugindir = $(plugindir)
 endif
 
-AM_CFLAGS = @DBUS_CFLAGS@ @GLIB_CFLAGS@ @USB_CFLAGS@ \
-					$(builtin_cflags) \
+AM_CFLAGS = @DBUS_CFLAGS@ @GLIB_CFLAGS@ $(builtin_cflags) \
 					-DOFONO_PLUGIN_BUILTIN \
 					-DPLUGINDIR=\""$(build_plugindir)"\"
 
diff --git a/configure.ac b/configure.ac
index 9b492fe3..7bf66d4c 100644
--- a/configure.ac
+++ b/configure.ac
@@ -116,12 +116,6 @@ AM_CONDITIONAL(TEST, test "${enable_test}" = "yes")
 
 AC_ARG_ENABLE(tools, AC_HELP_STRING([--enable-tools],
 		[enable testing tools]), [enable_tools=${enableval}])
-if (test "${enable_tools}" = "yes"); then
-	PKG_CHECK_MODULES(USB, libusb-1.0, dummy=yes,
-				AC_MSG_ERROR(USB library is required))
-	AC_SUBST(USB_CFLAGS)
-	AC_SUBST(USB_LIBS)
-fi
 AM_CONDITIONAL(TOOLS, test "${enable_tools}" = "yes")
 
 AC_ARG_ENABLE(dundee, AC_HELP_STRING([--enable-dundee],