diff --git a/json.go b/json.go
index f3971d1..2b78542 100644
--- a/json.go
+++ b/json.go
@@ -42,42 +42,3 @@ func appendJSONString(dst []byte, s string) []byte {
 	}
 	return append(dst, '"')
 }
-
-func appendJSONBytes(dst []byte, s []byte) []byte {
-	dst = append(dst, '"')
-	for i := 0; i < len(s); {
-		if b := s[i]; b < utf8.RuneSelf {
-			switch b {
-			case '"', '\\':
-				dst = append(dst, '\\', b)
-			case '\b':
-				dst = append(dst, '\\', 'b')
-			case '\f':
-				dst = append(dst, '\\', 'f')
-			case '\n':
-				dst = append(dst, '\\', 'n')
-			case '\r':
-				dst = append(dst, '\\', 'r')
-			case '\t':
-				dst = append(dst, '\\', 't')
-			default:
-				if b >= 0x20 {
-					dst = append(dst, b)
-				} else {
-					dst = append(dst, '\\', 'u', '0', '0', hex[b>>4], hex[b&0xF])
-				}
-			}
-			i++
-			continue
-		}
-		r, size := utf8.DecodeRune(s[i:])
-		if r == utf8.RuneError && size == 1 {
-			dst = append(dst, `\ufffd`...)
-			i++
-			continue
-		}
-		dst = append(dst, s[i:i+size]...)
-		i += size
-	}
-	return append(dst, '"')
-}
diff --git a/json_test.go b/json_test.go
new file mode 100644
index 0000000..fe12dee
--- /dev/null
+++ b/json_test.go
@@ -0,0 +1,51 @@
+package zerolog
+
+import "testing"
+
+func TestAppendJSONString(t *testing.T) {
+	encodeStringTests := []struct {
+		in  string
+		out string
+	}{
+		{"\\", `"\\"`},
+		{"\x00", `"\u0000"`},
+		{"\x01", `"\u0001"`},
+		{"\x02", `"\u0002"`},
+		{"\x03", `"\u0003"`},
+		{"\x04", `"\u0004"`},
+		{"\x05", `"\u0005"`},
+		{"\x06", `"\u0006"`},
+		{"\x07", `"\u0007"`},
+		{"\x08", `"\b"`},
+		{"\x09", `"\t"`},
+		{"\x0a", `"\n"`},
+		{"\x0b", `"\u000b"`},
+		{"\x0c", `"\f"`},
+		{"\x0d", `"\r"`},
+		{"\x0e", `"\u000e"`},
+		{"\x0f", `"\u000f"`},
+		{"\x10", `"\u0010"`},
+		{"\x11", `"\u0011"`},
+		{"\x12", `"\u0012"`},
+		{"\x13", `"\u0013"`},
+		{"\x14", `"\u0014"`},
+		{"\x15", `"\u0015"`},
+		{"\x16", `"\u0016"`},
+		{"\x17", `"\u0017"`},
+		{"\x18", `"\u0018"`},
+		{"\x19", `"\u0019"`},
+		{"\x1a", `"\u001a"`},
+		{"\x1b", `"\u001b"`},
+		{"\x1c", `"\u001c"`},
+		{"\x1d", `"\u001d"`},
+		{"\x1e", `"\u001e"`},
+		{"\x1f", `"\u001f"`},
+	}
+
+	for _, tt := range encodeStringTests {
+		b := appendJSONString([]byte{}, tt.in)
+		if got, want := string(b), tt.out; got != want {
+			t.Errorf("appendJSONString(%q) = %#q, want %#q", tt.in, got, want)
+		}
+	}
+}
diff --git a/log_test.go b/log_test.go
index c253ea5..4409b35 100644
--- a/log_test.go
+++ b/log_test.go
@@ -235,3 +235,35 @@ func TestLevelWriter(t *testing.T) {
 		t.Errorf("invalid ops:\ngot:\n%v\nwant:\n%v", got, want)
 	}
 }
+
+func TestContextTimestamp(t *testing.T) {
+	now = func() time.Time {
+		return time.Date(2001, time.February, 3, 4, 5, 6, 7, time.UTC)
+	}
+	defer func() {
+		now = time.Now
+	}()
+	out := &bytes.Buffer{}
+	log := New(out).With().Timestamp().Str("foo", "bar").Logger()
+	log.Log().Msg("hello world")
+
+	if got, want := out.String(), `{"time":981173106,"foo":"bar","message":"hello world"}`+"\n"; got != want {
+		t.Errorf("invalid log output: got %q, want %q", got, want)
+	}
+}
+
+func TestEventTimestamp(t *testing.T) {
+	now = func() time.Time {
+		return time.Date(2001, time.February, 3, 4, 5, 6, 7, time.UTC)
+	}
+	defer func() {
+		now = time.Now
+	}()
+	out := &bytes.Buffer{}
+	log := New(out).With().Str("foo", "bar").Logger()
+	log.Log().Timestamp().Msg("hello world")
+
+	if got, want := out.String(), `{"foo":"bar","time":981173106,"message":"hello world"}`+"\n"; got != want {
+		t.Errorf("invalid log output: got %q, want %q", got, want)
+	}
+}