diff --git a/middlewares/accesslog/logger_formatters.go b/middlewares/accesslog/logger_formatters.go
index a19dffc46..fcc63e6c9 100644
--- a/middlewares/accesslog/logger_formatters.go
+++ b/middlewares/accesslog/logger_formatters.go
@@ -9,7 +9,10 @@ import (
 )
 
 // default format for time presentation
-const commonLogTimeFormat = "02/Jan/2006:15:04:05 -0700"
+const (
+	commonLogTimeFormat = "02/Jan/2006:15:04:05 -0700"
+	defaultValue        = "-"
+)
 
 // CommonLogFormatter provides formatting in the Traefik common log format
 type CommonLogFormatter struct{}
@@ -21,27 +24,26 @@ func (f *CommonLogFormatter) Format(entry *logrus.Entry) ([]byte, error) {
 	timestamp := entry.Data[StartUTC].(time.Time).Format(commonLogTimeFormat)
 	elapsedMillis := entry.Data[Duration].(time.Duration).Nanoseconds() / 1000000
 
-	_, err := fmt.Fprintf(b, "%s - %s [%s] \"%s %s %s\" %d %d %s %s %d %s %s %dms\n",
+	_, err := fmt.Fprintf(b, "%s - %s [%s] \"%s %s %s\" %v %v %s %s %v %s %s %dms\n",
 		entry.Data[ClientHost],
 		entry.Data[ClientUsername],
 		timestamp,
 		entry.Data[RequestMethod],
 		entry.Data[RequestPath],
 		entry.Data[RequestProtocol],
-		entry.Data[OriginStatus],
-		entry.Data[OriginContentSize],
-		toLogString(entry.Data["request_Referer"]),
-		toLogString(entry.Data["request_User-Agent"]),
-		entry.Data[RequestCount],
-		toLogString(entry.Data[FrontendName]),
-		toLogString(entry.Data[BackendURL]),
+		toLog(entry.Data[OriginStatus]),
+		toLog(entry.Data[OriginContentSize]),
+		toLog(entry.Data["request_Referer"]),
+		toLog(entry.Data["request_User-Agent"]),
+		toLog(entry.Data[RequestCount]),
+		toLog(entry.Data[FrontendName]),
+		toLog(entry.Data[BackendURL]),
 		elapsedMillis)
 
 	return b.Bytes(), err
 }
 
-func toLogString(v interface{}) string {
-	defaultValue := "-"
+func toLog(v interface{}) interface{} {
 	if v == nil {
 		return defaultValue
 	}
@@ -54,7 +56,7 @@ func toLogString(v interface{}) string {
 		return quoted(s.String(), defaultValue)
 
 	default:
-		return defaultValue
+		return v
 	}
 
 }
diff --git a/middlewares/accesslog/logger_formatters_test.go b/middlewares/accesslog/logger_formatters_test.go
new file mode 100644
index 000000000..051d73850
--- /dev/null
+++ b/middlewares/accesslog/logger_formatters_test.go
@@ -0,0 +1,114 @@
+package accesslog
+
+import (
+	"net/http"
+	"testing"
+	"time"
+
+	"github.com/Sirupsen/logrus"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestCommonLogFormatter_Format(t *testing.T) {
+	clf := CommonLogFormatter{}
+
+	testCases := []struct {
+		name        string
+		data        map[string]interface{}
+		expectedLog string
+	}{
+		{
+			name: "OriginStatus & OriginContentSize are nil",
+			data: map[string]interface{}{
+				StartUTC:             time.Date(2009, time.November, 10, 23, 0, 0, 0, time.UTC),
+				Duration:             123 * time.Second,
+				ClientHost:           "10.0.0.1",
+				ClientUsername:       "Client",
+				RequestMethod:        http.MethodGet,
+				RequestPath:          "/foo",
+				RequestProtocol:      "http",
+				OriginStatus:         nil,
+				OriginContentSize:    nil,
+				"request_Referer":    "",
+				"request_User-Agent": "",
+				RequestCount:         0,
+				FrontendName:         "",
+				BackendURL:           "",
+			},
+			expectedLog: `10.0.0.1 - Client [10/Nov/2009:23:00:00 +0000] "GET /foo http" - - - - 0 - - 123000ms
+`,
+		},
+		{
+			name: "all data",
+			data: map[string]interface{}{
+				StartUTC:             time.Date(2009, time.November, 10, 23, 0, 0, 0, time.UTC),
+				Duration:             123 * time.Second,
+				ClientHost:           "10.0.0.1",
+				ClientUsername:       "Client",
+				RequestMethod:        http.MethodGet,
+				RequestPath:          "/foo",
+				RequestProtocol:      "http",
+				OriginStatus:         123,
+				OriginContentSize:    132,
+				"request_Referer":    "referer",
+				"request_User-Agent": "agent",
+				RequestCount:         nil,
+				FrontendName:         "foo",
+				BackendURL:           "http://10.0.0.2/toto",
+			},
+			expectedLog: `10.0.0.1 - Client [10/Nov/2009:23:00:00 +0000] "GET /foo http" 123 132 "referer" "agent" - "foo" "http://10.0.0.2/toto" 123000ms
+`,
+		},
+	}
+
+	for _, test := range testCases {
+		test := test
+		t.Run(test.name, func(t *testing.T) {
+			t.Parallel()
+
+			entry := &logrus.Entry{Data: test.data}
+
+			raw, err := clf.Format(entry)
+			assert.NoError(t, err)
+
+			assert.Equal(t, test.expectedLog, string(raw))
+		})
+	}
+
+}
+
+func Test_toLog(t *testing.T) {
+
+	testCases := []struct {
+		name        string
+		value       interface{}
+		expectedLog interface{}
+	}{
+		{
+			name:        "",
+			value:       1,
+			expectedLog: 1,
+		},
+		{
+			name:        "",
+			value:       "foo",
+			expectedLog: `"foo"`,
+		},
+		{
+			name:        "",
+			value:       nil,
+			expectedLog: "-",
+		},
+	}
+
+	for _, test := range testCases {
+		test := test
+		t.Run(test.name, func(t *testing.T) {
+			t.Parallel()
+
+			lg := toLog(test.value)
+
+			assert.Equal(t, test.expectedLog, lg)
+		})
+	}
+}