AC_PROG_LIBTOOL
# Obtain compiler/linker options for dependencies
-PKG_CHECK_MODULES(UDEV, udev)
-PKG_CHECK_MODULES(DRM, libdrm)
+PKG_CHECK_MODULES([LIBUDEV], [libudev])
+PKG_CHECK_MODULES([DRM], [libdrm])
AC_CONFIG_FILES([Makefile gbm.pc])
AC_OUTPUT