diff --git a/internal/users/cache/getusers.go b/internal/users/cache/getusers.go
index fd5af39f2..b219f23ee 100644
--- a/internal/users/cache/getusers.go
+++ b/internal/users/cache/getusers.go
@@ -3,6 +3,7 @@ package cache
 import (
 	"encoding/json"
 	"fmt"
+	"strings"
 	"time"
 
 	"go.etcd.io/bbolt"
@@ -42,6 +43,8 @@ func (c *Cache) UserByID(uid uint32) (UserDB, error) {
 
 // UserByName returns a user matching this name or an error if the database is corrupted or no entry was found.
 func (c *Cache) UserByName(name string) (UserDB, error) {
+	// authd uses lowercase usernames
+	name = strings.ToLower(name)
 	u, err := getUser(c, userByNameBucketName, name)
 	return u.UserDB, err
 }
diff --git a/pam/internal/adapter/userselection.go b/pam/internal/adapter/userselection.go
index 868280cb7..fd722efb6 100644
--- a/pam/internal/adapter/userselection.go
+++ b/pam/internal/adapter/userselection.go
@@ -3,6 +3,7 @@ package adapter
 import (
 	"context"
 	"fmt"
+	"strings"
 
 	"github.com/charmbracelet/bubbles/cursor"
 	"github.com/charmbracelet/bubbles/textinput"
@@ -148,7 +149,8 @@ func (m userSelectionModel) Username() string {
 	if m.clientType == InteractiveTerminal && !m.selected {
 		return ""
 	}
-	return m.Model.Value()
+	// authd uses lowercase usernames
+	return strings.ToLower(m.Model.Value())
 }
 
 // Focus sets the focus state on the model. We also mark as the user is not