diff --git a/src/net/http/cookie.go b/src/net/http/cookie.go
index e9fd599392..b7b0455ee1 100644
--- a/src/net/http/cookie.go
+++ b/src/net/http/cookie.go
@@ -247,7 +247,7 @@ func (c *Cookie) Valid() error {
 	if !isCookieNameValid(c.Name) {
 		return errors.New("http: invalid Cookie.Name")
 	}
-	if !validCookieExpires(c.Expires) {
+	if !c.Expires.IsZero() && !validCookieExpires(c.Expires) {
 		return errors.New("http: invalid Cookie.Expires")
 	}
 	for i := 0; i < len(c.Value); i++ {
diff --git a/src/net/http/cookie_test.go b/src/net/http/cookie_test.go
index 0db138e4f1..8fcf1faaa5 100644
--- a/src/net/http/cookie_test.go
+++ b/src/net/http/cookie_test.go
@@ -542,11 +542,14 @@ func TestCookieValid(t *testing.T) {
 	}{
 		{nil, false},
 		{&Cookie{Name: ""}, false},
-		{&Cookie{Name: "invalid-expires"}, false},
 		{&Cookie{Name: "invalid-value", Value: "foo\"bar"}, false},
 		{&Cookie{Name: "invalid-path", Path: "/foo;bar/"}, false},
 		{&Cookie{Name: "invalid-domain", Domain: "example.com:80"}, false},
-		{&Cookie{Name: "valid", Value: "foo", Path: "/bar", Domain: "example.com", Expires: time.Unix(0, 0)}, true},
+		{&Cookie{Name: "invalid-expiry", Value: "", Expires: time.Date(1600, 1, 1, 1, 1, 1, 1, time.UTC)}, false},
+		{&Cookie{Name: "valid-empty"}, true},
+		{&Cookie{Name: "valid-expires", Value: "foo", Path: "/bar", Domain: "example.com", Expires: time.Unix(0, 0)}, true},
+		{&Cookie{Name: "valid-max-age", Value: "foo", Path: "/bar", Domain: "example.com", MaxAge: 60}, true},
+		{&Cookie{Name: "valid-all-fields", Value: "foo", Path: "/bar", Domain: "example.com", Expires: time.Unix(0, 0), MaxAge: 0}, true},
 	}
 
 	for _, tt := range tests {