diff --git a/coordinator/core/diskencryption.go b/coordinator/core/diskencryption.go
index a16d808ae..89e77b4a5 100644
--- a/coordinator/core/diskencryption.go
+++ b/coordinator/core/diskencryption.go
@@ -2,6 +2,7 @@ package core
 
 import (
 	"fmt"
+	"strings"
 )
 
 // GetDiskUUID gets the disk's UUID.
@@ -14,7 +15,7 @@ func (c *Core) GetDiskUUID() (string, error) {
 	if err != nil {
 		return "", fmt.Errorf("cannot retrieve uuid of disk: %w", err)
 	}
-	return uuid, nil
+	return strings.ToLower(uuid), nil
 }
 
 // UpdateDiskPassphrase switches the initial random passphrase of the encrypted disk to a permanent passphrase.
diff --git a/state/mapper/mapper.go b/state/mapper/mapper.go
index eaf45c49c..21a3e166a 100644
--- a/state/mapper/mapper.go
+++ b/state/mapper/mapper.go
@@ -3,6 +3,7 @@ package mapper
 import (
 	"errors"
 	"fmt"
+	"strings"
 
 	cryptsetup "github.com/martinjungblut/go-cryptsetup"
 )
@@ -36,7 +37,7 @@ func (m *Mapper) IsLUKSDevice() bool {
 
 // GetUUID gets the device's UUID.
 func (m *Mapper) DiskUUID() string {
-	return m.device.GetUUID()
+	return strings.ToLower(m.device.GetUUID())
 }
 
 // FormatDisk formats the disk and adds passphrase in keyslot 0.