diff --git a/env.go b/env.go
index db5b253..ae12176 100644
--- a/env.go
+++ b/env.go
@@ -32,13 +32,22 @@ func (c *envConfig) Init(opts ...config.Option) error {
 	return nil
 }
 
-func (c *envConfig) Load(ctx context.Context) error {
+func (c *envConfig) Load(ctx context.Context, opts ...config.LoadOption) error {
 	for _, fn := range c.opts.BeforeLoad {
 		if err := fn(ctx, c); err != nil && !c.opts.AllowFail {
 			return err
 		}
 	}
 
+	options := config.NewLoadOptions(opts...)
+	mopts := []func(*mergo.Config){mergo.WithTypeCheck}
+	if options.Override {
+		mopts = append(mopts, mergo.WithOverride)
+	}
+	if options.Append {
+		mopts = append(mopts, mergo.WithAppendSlice)
+	}
+
 	src, err := rutil.Zero(c.opts.Struct)
 	if err == nil {
 		err = c.fillValues(ctx, reflect.ValueOf(src))
@@ -47,7 +56,8 @@ func (c *envConfig) Load(ctx context.Context) error {
 		return err
 	}
 
-	if err = mergo.Merge(c.opts.Struct, src, mergo.WithOverride, mergo.WithTypeCheck, mergo.WithAppendSlice); err != nil && !c.opts.AllowFail {
+	err = mergo.Merge(c.opts.Struct, src, mopts...)
+	if err != nil && !c.opts.AllowFail {
 		return err
 	}
 
@@ -290,7 +300,7 @@ func (c *envConfig) fillValues(ctx context.Context, valueOf reflect.Value) error
 	return nil
 }
 
-func (c *envConfig) Save(ctx context.Context) error {
+func (c *envConfig) Save(ctx context.Context, opts ...config.SaveOption) error {
 	for _, fn := range c.opts.BeforeSave {
 		if err := fn(ctx, c); err != nil && !c.opts.AllowFail {
 			return err
diff --git a/go.mod b/go.mod
index 7cd8c6a..fab22d2 100644
--- a/go.mod
+++ b/go.mod
@@ -4,5 +4,5 @@ go 1.16
 
 require (
 	github.com/imdario/mergo v0.3.12
-	github.com/unistack-org/micro/v3 v3.3.17
+	github.com/unistack-org/micro/v3 v3.4.0
 )
diff --git a/go.sum b/go.sum
index d490443..3e10b38 100644
--- a/go.sum
+++ b/go.sum
@@ -5,9 +5,9 @@ github.com/imdario/mergo v0.3.12 h1:b6R2BslTbIEToALKP7LxUvijTsNI9TAe80pLWN2g/HU=
 github.com/imdario/mergo v0.3.12/go.mod h1:jmQim1M+e3UYxmgPu/WyfjB3N3VflVyUjjjwH0dnCYA=
 github.com/patrickmn/go-cache v2.1.0+incompatible/go.mod h1:3Qf8kWWT7OJRJbdiICTKqZju1ZixQ/KpMGzzAfe6+WQ=
 github.com/silas/dag v0.0.0-20210121180416-41cf55125c34/go.mod h1:7RTUFBdIRC9nZ7/3RyRNH1bdqIShrDejd1YbLwgPS+I=
-github.com/unistack-org/micro/v3 v3.3.17 h1:WcyS7InP0DlS/JpRQGLh5sG6VstkdHJbgpMp+gmHmwg=
-github.com/unistack-org/micro/v3 v3.3.17/go.mod h1:022EOEZZ789hZY3yB5ZSMXU6jLiadBgcNB/cpediV3c=
-golang.org/x/net v0.0.0-20210423184538-5f58ad60dda6/go.mod h1:OJAsFXCWl8Ukc7SiCT/9KSuxbyM7479/AVlXFRxuMCk=
+github.com/unistack-org/micro/v3 v3.4.0 h1:z9F3lgAb2j4cZ1ib5qBj66JPYUAzR4sNIJqUDjVwyVQ=
+github.com/unistack-org/micro/v3 v3.4.0/go.mod h1:LXmPfbJnJNvL0kQs8HfnkV3Wya2Wb+C7keVq++RCZnk=
+golang.org/x/net v0.0.0-20210510120150-4163338589ed/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
 golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210423082822-04245dca01da/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=