diff --git a/0028-enable-discard-option-for-dom0-filesystems-by-defaul.patch b/0028-enable-discard-option-for-dom0-filesystems-by-defaul.patch
new file mode 100644
index 0000000..24e0b86
--- /dev/null
+++ b/0028-enable-discard-option-for-dom0-filesystems-by-defaul.patch
@@ -0,0 +1,33 @@
+From 633dc89cae0ebd597cc9069fdced3c8485ba5e46 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Marek=20Marczykowski-G=C3=B3recki?=
+ <marmarek@invisiblethingslab.com>
+Date: Wed, 25 Dec 2019 09:36:06 +0100
+Subject: [PATCH] enable discard option for dom0 filesystems by default
+
+This may have performance impact on some older SSD, but on the other
+hand, without this option it's pretty easy to fill the whole LVM thin
+pool even if there is plenty free space in dom0.
+Note that this doesn't enable it on LUKS layer, this is still disabled
+by default.
+
+Fixes QubesOS/qubes-issues#3226
+---
+ pyanaconda/storage/fsset.py | 2 ++
+ 1 file changed, 2 insertions(+)
+
+diff --git a/pyanaconda/storage/fsset.py b/pyanaconda/storage/fsset.py
+index 8d2390ddb..6117c6d0a 100644
+--- a/pyanaconda/storage/fsset.py
++++ b/pyanaconda/storage/fsset.py
+@@ -771,6 +771,8 @@ class FSSet(object):
+                     break
+             if device.encrypted:
+                 options += ",x-systemd.device-timeout=0"
++            if mountpoint.startswith('/'):
++                options += ",discard"
+             devspec = device.fstab_spec
+             dump = device.format.dump
+             if device.format.check and mountpoint == "/":
+-- 
+2.21.0
+
diff --git a/anaconda.spec.in b/anaconda.spec.in
index 8b2d93e..abf4223 100644
--- a/anaconda.spec.in
+++ b/anaconda.spec.in
@@ -48,6 +48,7 @@ Patch23: 0024-Do-not-mount-pre-existing-partitions-and-do-not-dete.patch
 Patch24: 0025-Set-encrypted-partitioning-by-default.patch
 Patch25: 0026-Set-default-hostname-to-dom0.patch
 Patch26: 0027-Setup-grubx64.efi-directly-as-a-bootloader.patch
+Patch27: 0028-enable-discard-option-for-dom0-filesystems-by-defaul.patch
 
 # Versions of required components (done so we make sure the buildrequires
 # match the requires versions of things).