diff --git a/user/go.mod b/user/go.mod
index ad6231c..c494b18 100644
--- a/user/go.mod
+++ b/user/go.mod
@@ -1,6 +1,6 @@
 module github.com/moby/sys/user
 
-go 1.18
+go 1.24
 
 require golang.org/x/sys v0.1.0
 
diff --git a/user/idtools_unix_test.go b/user/idtools_unix_test.go
index ef10085..c6cc5ca 100644
--- a/user/idtools_unix_test.go
+++ b/user/idtools_unix_test.go
@@ -5,6 +5,7 @@ package user
 import (
 	"errors"
 	"fmt"
+	"maps"
 	"os"
 	"path/filepath"
 	"testing"
@@ -292,9 +293,7 @@ func readTree(base, root string) (map[string]node, error) {
 			if err != nil {
 				return nil, err
 			}
-			for path, nodeinfo := range subtree {
-				tree[path] = nodeinfo
-			}
+			maps.Copy(tree, subtree)
 		}
 	}
 	return tree, nil
diff --git a/user/user.go b/user/user.go
index e747767..48c34a8 100644
--- a/user/user.go
+++ b/user/user.go
@@ -7,6 +7,7 @@ import (
 	"fmt"
 	"io"
 	"os"
+	"slices"
 	"strconv"
 	"strings"
 )
@@ -352,12 +353,7 @@ func GetExecUser(userSpec string, defaults *ExecUser, passwd, group io.Reader) (
 			// If the group argument isn't explicit, we'll just search for it.
 			if groupArg == nil {
 				// Check if user is a member of this group.
-				for _, u := range g.List {
-					if u == matchedUserName {
-						return true
-					}
-				}
-				return false
+				return slices.Contains(g.List, matchedUserName)
 			}
 			return groupArg.matches(g)
 		})