diff --git a/tuned.spec b/tuned.spec
index 23d3149..5e2c284 100644
--- a/tuned.spec
+++ b/tuned.spec
@@ -147,8 +147,10 @@ rmdir %{buildroot}%{_sysconfdir}/grub.d
 sed -i 's|.*/\([^/]\+\)/[^\.]\+\.conf|\1|' /etc/tuned/active_profile
 
 # convert GRUB_CMDLINE_LINUX to GRUB_CMDLINE_LINUX_DEFAULT
-sed -i 's/GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX \\$tuned_params"/GRUB_CMDLINE_LINUX_DEFAULT="$GRUB_CMDLINE_LINUX_DEFAULT \\$tuned_params"/' \
-  %{_sysconfdir}/default/grub
+if [ -r "%{_sysconfdir}/default/grub" ]; then
+  sed -i 's/GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX \\$tuned_params"/GRUB_CMDLINE_LINUX_DEFAULT="$GRUB_CMDLINE_LINUX_DEFAULT \\$tuned_params"/' \
+    %{_sysconfdir}/default/grub
+fi
 
 
 %preun
@@ -163,7 +165,9 @@ sed -i 's/GRUB_CMDLINE_LINUX="$GRUB_CMDLINE_LINUX \\$tuned_params"/GRUB_CMDLINE_
 if [ "$1" == 0 ]; then
   rm -f %{_sysconfdir}/grub.d/00_tuned || :
 # unpatch /etc/default/grub
-  sed -i '/GRUB_CMDLINE_LINUX_DEFAULT="$GRUB_CMDLINE_LINUX_DEFAULT \\$tuned_params"/d' %{_sysconfdir}/default/grub
+  if [ -r "%{_sysconfdir}/default/grub" ]; then
+    sed -i '/GRUB_CMDLINE_LINUX_DEFAULT="$GRUB_CMDLINE_LINUX_DEFAULT \\$tuned_params"/d' %{_sysconfdir}/default/grub
+  fi
 fi