diff --git a/json_formatter.go b/json_formatter.go
index 0e38a61..5c4c44b 100644
--- a/json_formatter.go
+++ b/json_formatter.go
@@ -11,11 +11,12 @@
 func (f *JSONFormatter) Format(entry *Entry) ([]byte, error) {
 	data := make(Fields, len(entry.Data)+3)
 	for k, v := range entry.Data {
-		// Otherwise errors are ignored by `encoding/json`
-		// https://github.com/Sirupsen/logrus/issues/137
-		if err, ok := v.(error); ok {
-			data[k] = err.Error()
-		} else {
+		switch v := v.(type) {
+		case error:
+			// Otherwise errors are ignored by `encoding/json`
+			// https://github.com/Sirupsen/logrus/issues/137
+			data[k] = v.Error()
+		default:
 			data[k] = v
 		}
 	}
diff --git a/terminal_openbsd.go b/terminal_openbsd.go
index d238bfa..af609a5 100644
--- a/terminal_openbsd.go
+++ b/terminal_openbsd.go
@@ -1,4 +1,3 @@
-
 package logrus
 
 import "syscall"
diff --git a/writer.go b/writer.go
index 90d3e01..1e30b1c 100644
--- a/writer.go
+++ b/writer.go
@@ -6,7 +6,7 @@
 	"runtime"
 )
 
-func (logger *Logger) Writer() (*io.PipeWriter) {
+func (logger *Logger) Writer() *io.PipeWriter {
 	reader, writer := io.Pipe()
 
 	go logger.writerScanner(reader)