diff --git a/cmd/docker-buildx/config.go b/cmd/docker-buildx/config.go
index 87046d0..7c7b219 100644
--- a/cmd/docker-buildx/config.go
+++ b/cmd/docker-buildx/config.go
@@ -183,7 +183,7 @@ func settingsFlags(settings *plugin.Settings) []cli.Flag {
 			Usage:       "forwards environment variables as custom arguments to the build",
 			Destination: &settings.Build.ArgsEnv,
 		},
-		&cli.StringSliceFlag{
+		&cli.StringFlag{
 			Name:        "secret",
 			EnvVars:     []string{"PLUGIN_SECRET"},
 			Usage:       "sets custom secret argument for the build",