diff --git a/diskimage_builder/elements/bootloader/README.rst b/diskimage_builder/elements/bootloader/README.rst
index ce2147bc..56e17076 100644
--- a/diskimage_builder/elements/bootloader/README.rst
+++ b/diskimage_builder/elements/bootloader/README.rst
@@ -13,6 +13,6 @@ Arguments
 * ``DIB_GRUB_TIMEOUT`` sets the ``grub`` menu timeout.  It defaults to
   5 seconds.  Set this to 0 (no timeout) for fast boot times.
 
-* ``DIB_BOOTLOADER_DEFAULT_CMDLINE`` sets the CMDLINE parameters that
-  are appended to the grub.cfg configuration. It defaults to
-  'nofb nomodeset vga=normal'
+* ``DIB_BOOTLOADER_DEFAULT_CMDLINE`` sets parameters that are appended
+  to the ``GRUB_CMDLINE_LINUX_DEFAULT`` values in ``grub.cfg``
+  configuration. It defaults to ``nofb nomodeset vga=normal``.
diff --git a/diskimage_builder/elements/bootloader/finalise.d/50-bootloader b/diskimage_builder/elements/bootloader/finalise.d/50-bootloader
index 0a6b0db6..75dfd78c 100755
--- a/diskimage_builder/elements/bootloader/finalise.d/50-bootloader
+++ b/diskimage_builder/elements/bootloader/finalise.d/50-bootloader
@@ -185,9 +185,8 @@ function install_grub2 {
 
     GRUB_CMDLINE_LINUX_DEFAULT="console=tty0 console=${SERIAL_CONSOLE} no_timer_check"
 
-    echo "GRUB_CMDLINE_LINUX_DEFAULT=\"${GRUB_CMDLINE_LINUX_DEFAULT}\"" >>/etc/default/grub
+    echo "GRUB_CMDLINE_LINUX_DEFAULT=\"${GRUB_CMDLINE_LINUX_DEFAULT} ${DIB_BOOTLOADER_DEFAULT_CMDLINE}\"" >>/etc/default/grub
     echo 'GRUB_SERIAL_COMMAND="serial --speed=115200 --unit=0 --word=8 --parity=no --stop=1"' >>/etc/default/grub
-    sed -i -e "s/\(^GRUB_CMDLINE_LINUX.*\)\"$/\1 ${DIB_BOOTLOADER_DEFAULT_CMDLINE}\"/" /etc/default/grub
 
     if type grub2-mkconfig >/dev/null; then
         GRUB_MKCONFIG="grub2-mkconfig -o $GRUB_CFG"
diff --git a/releasenotes/notes/bootloader-commandline-d2db7524f1f9ad28.yaml b/releasenotes/notes/bootloader-commandline-d2db7524f1f9ad28.yaml
new file mode 100644
index 00000000..643d22b9
--- /dev/null
+++ b/releasenotes/notes/bootloader-commandline-d2db7524f1f9ad28.yaml
@@ -0,0 +1,7 @@
+---
+other:
+  - It has been clarified that the ``DIB_BOOTLOADER_DEFAULT_CMDLINE``
+    variable appends its values to grubs
+    ``GRUB_CMDLINE_LINUX_DEFAULT``, which is used during all normal
+    boots but not rescue boots; as opposed to applying to
+    ``GRUB_CMDLINE_LINUX``