diff --git a/cli/command/manifest/annotate.go b/cli/command/manifest/annotate.go
index 9bdb7b1d26cc..231aa930621f 100644
--- a/cli/command/manifest/annotate.go
+++ b/cli/command/manifest/annotate.go
@@ -48,27 +48,6 @@ func newManifestStore(dockerCLI command.Cli) store.Store {
 	return store.NewStore(filepath.Join(config.Dir(), "manifests"))
 }
 
-// authConfigKey is the key used to store credentials for Docker Hub. It is
-// a copy of [registry.IndexServer].
-//
-// [registry.IndexServer]: https://pkg.go.dev/github.com/docker/docker@v28.3.3+incompatible/registry#IndexServer
-const authConfigKey = "https://index.docker.io/v1/"
-
-// getAuthConfigKey special-cases using the full index address of the official
-// index as the AuthConfig key, and uses the (host)name[:port] for private indexes.
-//
-// It is similar to [registry.GetAuthConfigKey], but does not require on
-// [registrytypes.IndexInfo] as intermediate.
-//
-// [registry.GetAuthConfigKey]: https://pkg.go.dev/github.com/docker/docker@v28.3.3+incompatible/registry#GetAuthConfigKey
-// [registrytypes.IndexInfo]: https://pkg.go.dev/github.com/docker/docker@v28.3.3+incompatible/api/types/registry#IndexInfo
-func getAuthConfigKey(domainName string) string {
-	if domainName == "docker.io" || domainName == "index.docker.io" {
-		return authConfigKey
-	}
-	return domainName
-}
-
 // newRegistryClient returns a client for communicating with a Docker distribution
 // registry
 func newRegistryClient(dockerCLI command.Cli, allowInsecure bool) registryclient.RegistryClient {
@@ -78,8 +57,7 @@ func newRegistryClient(dockerCLI command.Cli, allowInsecure bool) registryclient
 	}
 	cfg := dockerCLI.ConfigFile()
 	resolver := func(ctx context.Context, domainName string) registry.AuthConfig {
-		configKey := getAuthConfigKey(domainName)
-		a, _ := cfg.GetAuthConfig(configKey)
+		a, _ := cfg.GetAuthConfig(domainName)
 		return registry.AuthConfig{
 			Username:      a.Username,
 			Password:      a.Password,