diff --git a/grub.macros b/grub.macros
index 1aebb51..d8b4b61 100644
--- a/grub.macros
+++ b/grub.macros
@@ -84,9 +84,9 @@
 ### fixme
 %global efi_modules_base http lsefimmap
 %ifarch aarch64 %{arm}
-%global efi_modules "%{efi_modules_base} linux "
+%global efi_modules %{efi_modules_base} linux
 %else
-%global efi_modules "%{efi_modules_base} backtrace linuxefi usb usbserial_common usbserial_pl2303 usbserial_ftdi usbserial_usbdebug "
+%global efi_modules %{efi_modules_base} backtrace linuxefi usb usbserial_common usbserial_pl2303 usbserial_ftdi usbserial_usbdebug
 %endif
 
 %ifarch aarch64
@@ -349,7 +349,7 @@ GRUB_MODULES="	all_video boot blscfg btrfs			\\\
 		search search_fs_uuid search_fs_file		\\\
 		search_label serial sleep syslinuxcfg test tftp \\\
 		video xfs"					\
-GRUB_MODULES+=" %{efi_modules}"					\
+GRUB_MODULES+=" %{efi_modules} "				\
 %{expand:%%{mkimage %{1} %{2} %{3} %{4}}}			\
 %{nil}