diff --git a/internal/app/wwctl/root.go b/internal/app/wwctl/root.go
index cd86b128..d225e7df 100644
--- a/internal/app/wwctl/root.go
+++ b/internal/app/wwctl/root.go
@@ -15,6 +15,7 @@ import (
 	"github.com/warewulf/warewulf/internal/app/wwctl/profile"
 	"github.com/warewulf/warewulf/internal/app/wwctl/server"
 	"github.com/warewulf/warewulf/internal/app/wwctl/ssh"
+	"github.com/warewulf/warewulf/internal/app/wwctl/upgrade"
 	"github.com/warewulf/warewulf/internal/app/wwctl/version"
 	warewulfconf "github.com/warewulf/warewulf/internal/pkg/config"
 	"github.com/warewulf/warewulf/internal/pkg/help"
@@ -60,6 +61,7 @@ func init() {
 	rootCmd.AddCommand(ssh.GetCommand())
 	rootCmd.AddCommand(genconf.GetCommand())
 	rootCmd.AddCommand(clean.GetCommand())
+	rootCmd.AddCommand(upgrade.Command)
 }
 
 // GetRootCommand returns the root cobra.Command for the application.
diff --git a/internal/app/wwctl/upgrade/cobra.go b/internal/app/wwctl/upgrade/cobra.go
new file mode 100644
index 00000000..22b57d6f
--- /dev/null
+++ b/internal/app/wwctl/upgrade/cobra.go
@@ -0,0 +1,48 @@
+package upgrade
+
+import (
+	"os"
+
+	"github.com/spf13/cobra"
+
+	"github.com/warewulf/warewulf/internal/pkg/node"
+	libupgrade "github.com/warewulf/warewulf/internal/pkg/upgrade"
+	"github.com/warewulf/warewulf/internal/pkg/util"
+)
+
+var (
+	Command = &cobra.Command{
+		DisableFlagsInUseLine: true,
+		Use:                   "upgrade [OPTIONS]",
+		Short:                 "Upgrade an existing nodes.conf",
+		Long: `Upgrades nodes.conf from a previous version of Warewulf 4 to a format
+supported by the current version.`,
+		RunE: UpgradeNodesConf,
+	}
+
+	addDefaults bool
+	inputPath   string
+	outputPath  string
+)
+
+func init() {
+	Command.Flags().BoolVar(&addDefaults, "add-defaults", false, "Configure a default profile and set default node values")
+	Command.Flags().StringVarP(&inputPath, "input-path", "i", node.ConfigFile, "Path to a legacy nodes.conf")
+	Command.Flags().StringVarP(&outputPath, "output-path", "o", node.ConfigFile, "Path to write the upgraded nodes.conf to")
+}
+
+func UpgradeNodesConf(cmd *cobra.Command, args []string) error {
+	data, err := os.ReadFile(inputPath)
+	if err != nil {
+		return err
+	}
+	legacy, err := libupgrade.Parse(data)
+	if err != nil {
+		return err
+	}
+	upgraded := legacy.Upgrade(addDefaults)
+	if err := util.CopyFile(outputPath, outputPath+"-old"); err != nil {
+		return err
+	}
+	return upgraded.PersistToFile(outputPath)
+}
diff --git a/internal/pkg/node/constructors.go b/internal/pkg/node/constructors.go
index 7e7c6b0c..7e00ed7a 100644
--- a/internal/pkg/node/constructors.go
+++ b/internal/pkg/node/constructors.go
@@ -18,14 +18,17 @@ var (
 	ConfigFile string
 )
 
-/*
-Creates a new nodeDb object from the on-disk configuration
-*/
-func New() (NodesYaml, error) {
+func init() {
 	conf := warewulfconf.Get()
 	if ConfigFile == "" {
 		ConfigFile = path.Join(conf.Paths.Sysconfdir, "warewulf/nodes.conf")
 	}
+}
+
+/*
+Creates a new nodeDb object from the on-disk configuration
+*/
+func New() (NodesYaml, error) {
 	wwlog.Verbose("Opening node configuration file: %s", ConfigFile)
 	data, err := os.ReadFile(ConfigFile)
 	if err != nil {
diff --git a/internal/pkg/node/modifiers.go b/internal/pkg/node/modifiers.go
index be44d520..1bd5e03b 100644
--- a/internal/pkg/node/modifiers.go
+++ b/internal/pkg/node/modifiers.go
@@ -109,12 +109,19 @@ func (config *NodesYaml) DelProfile(nodeID string) error {
 Write the the NodeYaml to disk.
 */
 func (config *NodesYaml) Persist() error {
+	return config.PersistToFile(ConfigFile)
+}
+
+func (config *NodesYaml) PersistToFile(configFile string) error {
+	if configFile == "" {
+		configFile = ConfigFile
+	}
 	out, dumpErr := config.Dump()
 	if dumpErr != nil {
 		wwlog.Error("%s", dumpErr)
 		return dumpErr
 	}
-	file, err := os.OpenFile(ConfigFile, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0o644)
+	file, err := os.OpenFile(configFile, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0o644)
 	if err != nil {
 		wwlog.Error("%s", err)
 		return err
@@ -124,7 +131,7 @@ func (config *NodesYaml) Persist() error {
 	if err != nil {
 		return err
 	}
-	wwlog.Debug("persisted: %s", ConfigFile)
+	wwlog.Debug("persisted: %s", configFile)
 	return nil
 }
 
diff --git a/internal/pkg/upgrade/node_test.go b/internal/pkg/upgrade/node_test.go
index 334199ed..4e1d99dd 100644
--- a/internal/pkg/upgrade/node_test.go
+++ b/internal/pkg/upgrade/node_test.go
@@ -616,7 +616,8 @@ func Test_UpgradeNodesYaml(t *testing.T) {
 			legacy, err := Parse([]byte(tt.legacyYaml))
 			assert.NoError(t, err)
 			upgraded := legacy.Upgrade(tt.addDefaults)
-			upgradedYaml, _ := upgraded.Dump()
+			upgradedYaml, err := upgraded.Dump()
+			assert.NoError(t, err)
 			assert.Equal(t, strings.TrimSpace(tt.upgradedYaml), strings.TrimSpace(string(upgradedYaml)))
 		})
 	}