diff --git a/jsonlog/jsonlog.go b/jsonlog/jsonlog.go
index 422e4bb..4734c31 100644
--- a/jsonlog/jsonlog.go
+++ b/jsonlog/jsonlog.go
@@ -15,6 +15,8 @@ type JSONLog struct {
 	Stream string `json:"stream,omitempty"`
 	// Created is the created timestamp of log
 	Created time.Time `json:"time"`
+	// Attrs is the list of extra attributes provided by the user
+	Attrs map[string]string `json:"attrs,omitempty"`
 }
 
 // Format returns the log formatted according to format
diff --git a/jsonlog/jsonlog_marshalling_test.go b/jsonlog/jsonlog_marshalling_test.go
index 5e45568..3edb271 100644
--- a/jsonlog/jsonlog_marshalling_test.go
+++ b/jsonlog/jsonlog_marshalling_test.go
@@ -6,18 +6,18 @@ import (
 )
 
 func TestJSONLogMarshalJSON(t *testing.T) {
-	logs := map[JSONLog]string{
-		JSONLog{Log: `"A log line with \\"`}:           `^{\"log\":\"\\\"A log line with \\\\\\\\\\\"\",\"time\":\".{20,}\"}$`,
-		JSONLog{Log: "A log line"}:                     `^{\"log\":\"A log line\",\"time\":\".{20,}\"}$`,
-		JSONLog{Log: "A log line with \r"}:             `^{\"log\":\"A log line with \\r\",\"time\":\".{20,}\"}$`,
-		JSONLog{Log: "A log line with & < >"}:          `^{\"log\":\"A log line with \\u0026 \\u003c \\u003e\",\"time\":\".{20,}\"}$`,
-		JSONLog{Log: "A log line with utf8 : 🚀 ψ ω β"}: `^{\"log\":\"A log line with utf8 : 🚀 ψ ω β\",\"time\":\".{20,}\"}$`,
-		JSONLog{Stream: "stdout"}:                      `^{\"stream\":\"stdout\",\"time\":\".{20,}\"}$`,
-		JSONLog{}:                                      `^{\"time\":\".{20,}\"}$`,
+	logs := map[*JSONLog]string{
+		&JSONLog{Log: `"A log line with \\"`}:           `^{\"log\":\"\\\"A log line with \\\\\\\\\\\"\",\"time\":\".{20,}\"}$`,
+		&JSONLog{Log: "A log line"}:                     `^{\"log\":\"A log line\",\"time\":\".{20,}\"}$`,
+		&JSONLog{Log: "A log line with \r"}:             `^{\"log\":\"A log line with \\r\",\"time\":\".{20,}\"}$`,
+		&JSONLog{Log: "A log line with & < >"}:          `^{\"log\":\"A log line with \\u0026 \\u003c \\u003e\",\"time\":\".{20,}\"}$`,
+		&JSONLog{Log: "A log line with utf8 : 🚀 ψ ω β"}: `^{\"log\":\"A log line with utf8 : 🚀 ψ ω β\",\"time\":\".{20,}\"}$`,
+		&JSONLog{Stream: "stdout"}:                      `^{\"stream\":\"stdout\",\"time\":\".{20,}\"}$`,
+		&JSONLog{}:                                      `^{\"time\":\".{20,}\"}$`,
 		// These ones are a little weird
-		JSONLog{Log: "\u2028 \u2029"}:      `^{\"log\":\"\\u2028 \\u2029\",\"time\":\".{20,}\"}$`,
-		JSONLog{Log: string([]byte{0xaF})}: `^{\"log\":\"\\ufffd\",\"time\":\".{20,}\"}$`,
-		JSONLog{Log: string([]byte{0x7F})}: `^{\"log\":\"\x7f\",\"time\":\".{20,}\"}$`,
+		&JSONLog{Log: "\u2028 \u2029"}:      `^{\"log\":\"\\u2028 \\u2029\",\"time\":\".{20,}\"}$`,
+		&JSONLog{Log: string([]byte{0xaF})}: `^{\"log\":\"\\ufffd\",\"time\":\".{20,}\"}$`,
+		&JSONLog{Log: string([]byte{0x7F})}: `^{\"log\":\"\x7f\",\"time\":\".{20,}\"}$`,
 	}
 	for jsonLog, expression := range logs {
 		data, err := jsonLog.MarshalJSON()