diff --git a/core/mapping/unmarshaler.go b/core/mapping/unmarshaler.go
index a4cdf3f6..2cd1b93e 100644
--- a/core/mapping/unmarshaler.go
+++ b/core/mapping/unmarshaler.go
@@ -25,9 +25,9 @@ var (
 	errValueNotStruct   = errors.New("value type is not struct")
 	keyUnmarshaler      = NewUnmarshaler(defaultKeyName)
 	durationType        = reflect.TypeOf(time.Duration(0))
-	cacheKeys           map[string][]string
+	cacheKeys           = make(map[string][]string)
 	cacheKeysLock       sync.Mutex
-	defaultCache        map[string]interface{}
+	defaultCache        = make(map[string]interface{})
 	defaultCacheLock    sync.Mutex
 	emptyMap            = map[string]interface{}{}
 	emptyValue          = reflect.ValueOf(lang.Placeholder)
@@ -49,11 +49,6 @@ type (
 	}
 )
 
-func init() {
-	cacheKeys = make(map[string][]string)
-	defaultCache = make(map[string]interface{})
-}
-
 // NewUnmarshaler returns a Unmarshaler.
 func NewUnmarshaler(key string, opts ...UnmarshalOption) *Unmarshaler {
 	unmarshaler := Unmarshaler{
diff --git a/rest/internal/encoding/parser_test.go b/rest/internal/encoding/parser_test.go
index b04b3f72..2708098c 100644
--- a/rest/internal/encoding/parser_test.go
+++ b/rest/internal/encoding/parser_test.go
@@ -48,4 +48,4 @@ func TestParseHeadersArrayInt(t *testing.T) {
 	r.Header.Add("foo", "2")
 	assert.Nil(t, ParseHeaders(r.Header, &val))
 	assert.Equal(t, []int{1, 2}, val.Foo)
-}
\ No newline at end of file
+}
diff --git a/zrpc/internal/rpclogger.go b/zrpc/internal/rpclogger.go
index e7b057bb..e3c3148c 100644
--- a/zrpc/internal/rpclogger.go
+++ b/zrpc/internal/rpclogger.go
@@ -1,8 +1,6 @@
 package internal
 
 import (
-	"sync"
-
 	"github.com/zeromicro/go-zero/core/logx"
 	"google.golang.org/grpc/grpclog"
 )
@@ -10,16 +8,11 @@ import (
 // because grpclog.errorLog is not exported, we need to define our own.
 const errorLevel = 2
 
-var once sync.Once
-
 // A Logger is a rpc logger.
 type Logger struct{}
 
-// InitLogger initializes the rpc logger.
-func InitLogger() {
-	once.Do(func() {
-		grpclog.SetLoggerV2(new(Logger))
-	})
+func init() {
+	grpclog.SetLoggerV2(new(Logger))
 }
 
 // Error logs the given args into error log.
diff --git a/zrpc/internal/rpcserver.go b/zrpc/internal/rpcserver.go
index 36408776..cf9c8ce8 100644
--- a/zrpc/internal/rpcserver.go
+++ b/zrpc/internal/rpcserver.go
@@ -25,10 +25,6 @@ type (
 	}
 )
 
-func init() {
-	InitLogger()
-}
-
 // NewRpcServer returns a Server.
 func NewRpcServer(address string, opts ...ServerOption) Server {
 	var options rpcServerOptions