diff --git a/log/filter.go b/log/filter.go
index 9ef87ddf1..ab5723770 100644
--- a/log/filter.go
+++ b/log/filter.go
@@ -66,13 +66,13 @@ func (f *Filter) Log(level Level, keyvals ...interface{}) error {
 	}
 	// fkv is used to provide a slice to contains both logger.prefix and keyvals for filter
 	var fkv []interface{}
-	if l, ok := f.logger.(*logger); ok {
-		if len(l.prefix) > 0 {
-			fkv = make([]interface{}, 0, len(l.prefix)+len(keyvals))
-			fkv = append(fkv, l.prefix...)
-			fkv = append(fkv, keyvals...)
-		}
-	} else {
+	l, ok := f.logger.(*logger)
+	if ok && len(l.prefix) > 0 {
+		fkv = make([]interface{}, 0, len(l.prefix)+len(keyvals))
+		fkv = append(fkv, l.prefix...)
+		fkv = append(fkv, keyvals...)
+	}
+	if !ok {
 		fkv = keyvals
 	}
 	if f.filter != nil && f.filter(level, fkv...) {
diff --git a/log/helper_writer.go b/log/helper_writer.go
index 0c76a7bae..5ab45802d 100644
--- a/log/helper_writer.go
+++ b/log/helper_writer.go
@@ -19,9 +19,7 @@ func WithWriterLevel(level Level) WriterOptionFn {
 // WithWriteMessageKey set writerWrapper helper message key.
 func WithWriteMessageKey(key string) WriterOptionFn {
 	return func(w *writerWrapper) {
-		if key != "" {
-			w.helper.msgKey = key
-		}
+		w.helper.msgKey = key
 	}
 }
 
diff --git a/log/log.go b/log/log.go
index 1b612f8b8..2a290b707 100644
--- a/log/log.go
+++ b/log/log.go
@@ -37,32 +37,34 @@ func (c *logger) Log(level Level, keyvals ...interface{}) error {
 
 // With with logger fields.
 func With(l Logger, kv ...interface{}) Logger {
-	if c, ok := l.(*logger); ok {
-		kvs := make([]interface{}, 0, len(c.prefix)+len(kv))
-		kvs = append(kvs, kv...)
-		kvs = append(kvs, c.prefix...)
-		return &logger{
-			logs:      c.logs,
-			prefix:    kvs,
-			hasValuer: containsValuer(kvs),
-			ctx:       c.ctx,
-		}
+	c, ok := l.(*logger)
+	if !ok {
+		return &logger{logs: []Logger{l}, prefix: kv, hasValuer: containsValuer(kv)}
+	}
+	kvs := make([]interface{}, 0, len(c.prefix)+len(kv))
+	kvs = append(kvs, kv...)
+	kvs = append(kvs, c.prefix...)
+	return &logger{
+		logs:      c.logs,
+		prefix:    kvs,
+		hasValuer: containsValuer(kvs),
+		ctx:       c.ctx,
 	}
-	return &logger{logs: []Logger{l}, prefix: kv, hasValuer: containsValuer(kv)}
 }
 
 // WithContext returns a shallow copy of l with its context changed
 // to ctx. The provided ctx must be non-nil.
 func WithContext(ctx context.Context, l Logger) Logger {
-	if c, ok := l.(*logger); ok {
-		return &logger{
-			logs:      c.logs,
-			prefix:    c.prefix,
-			hasValuer: c.hasValuer,
-			ctx:       ctx,
-		}
+	c, ok := l.(*logger)
+	if !ok {
+		return &logger{logs: []Logger{l}, ctx: ctx}
+	}
+	return &logger{
+		logs:      c.logs,
+		prefix:    c.prefix,
+		hasValuer: c.hasValuer,
+		ctx:       ctx,
 	}
-	return &logger{logs: []Logger{l}, ctx: ctx}
 }
 
 // MultiLogger wraps multi logger.