diff --git a/playwright.go b/playwright.go
index 26c0820..df8fb4b 100644
--- a/playwright.go
+++ b/playwright.go
@@ -122,12 +122,17 @@ func playwrightSameSiteToSameSite(s *playwright.SameSiteAttribute) SameSite {
 }
 
 func cookieToPlaywrightOptionalCookie(cookie Cookie) playwright.OptionalCookie {
+	expires := float64(cookie.Expires.Unix())
+	if cookie.Expires.IsZero() || expires <= 0 {
+		expires = -1
+	}
+
 	oc := playwright.OptionalCookie{
 		Name:     cookie.Name,
 		Value:    cookie.Value,
 		Domain:   playwright.String(cookie.Host),
 		Path:     playwright.String(cookie.Path),
-		Expires:  playwright.Float(float64(cookie.Expires.Unix())),
+		Expires:  playwright.Float(expires),
 		Secure:   playwright.Bool(cookie.Secure),
 		HttpOnly: playwright.Bool(cookie.HttpOnly),
 	}