diff --git a/extra/efivar/build b/extra/efivar/build
index 762b19f8..d053d44e 100755
--- a/extra/efivar/build
+++ b/extra/efivar/build
@@ -3,7 +3,8 @@
 # LTO is used when CFLAGS are unset causing a compilation
 # error with GCC 10. LTO can be set by the user though
 # '-flto-partition=none' is also needed.
-sed -i 's/ -flto//' Make.defaults
+sed 's/ -flto//' Make.defaults > _
+mv -f _ Make.defaults
 
 for patch in *.patch; do
     patch -p1 < "$patch"