diff --git a/20-grub.install b/20-grub.install
index 8ae388530da12974996958e87554f00024152805..819c3632b9167f0217b4fe9a4fe94830e9002a2b 100644
--- a/20-grub.install
+++ b/20-grub.install
@@ -113,7 +113,8 @@ case "$COMMAND" in
                 sed -i -e "s,^initrd.*,initrd ${BOOTPREFIX}${INITRD},g" "${BLS_TARGET}"
             fi
 
-            if [[ "$KERNEL_VERSION" == *\+* ]] && [ "x$GRUB_DEFAULT_TO_DEBUG" != "xtrue" ]; then
+            # Only match debug kernel, ignore kernel-4k and kernel-64k here
+            if [[ "$KERNEL_VERSION" == *\+debug* ]] && [ "x$GRUB_DEFAULT_TO_DEBUG" != "xtrue" ]; then
                 GRUB_UPDATE_DEFAULT_KERNEL=false
             fi
 
diff --git a/grub2.spec b/grub2.spec
index b959e1dc95d6ae3e2bb516380f2a303a15e7aa1c..84ea8c7d80fb9a91b7c5f0db6686db6fd0a2a4c4 100644
--- a/grub2.spec
+++ b/grub2.spec
@@ -23,7 +23,7 @@
 Name:		grub2
 Epoch:		1
 Version:	2.12
-Release:	44
+Release:	45
 Summary:	Bootloader with support for Linux, Multiboot and more
 License:	GPLv3+
 URL:		http://www.gnu.org/software/grub/
@@ -464,6 +464,9 @@ fi
 %{_datadir}/man/man*
 
 %changelog
+* Mon Sep 29 2025 Qin Fandong <qinfandong@kylinos.cn> - 1:2.12-45
+- 20-grub.install: also set kernel-4k and kernel-64k as default
+
 * Mon Aug 18 2025 zhangqiumiao <zhangqiumiao1@h-partners.com> - 1:2.12-44
 - Type:bugfix
 - CVE:NA