diff --git a/acme4j-client/src/main/java/org/shredzone/acme4j/Order.java b/acme4j-client/src/main/java/org/shredzone/acme4j/Order.java
index f8c8e418..faf66a41 100644
--- a/acme4j-client/src/main/java/org/shredzone/acme4j/Order.java
+++ b/acme4j-client/src/main/java/org/shredzone/acme4j/Order.java
@@ -45,6 +45,7 @@ public class Order extends AcmeJsonResource {
      * <p>
      * Possible values are: {@link Status#PENDING}, {@link Status#READY},
      * {@link Status#PROCESSING}, {@link Status#VALID}, {@link Status#INVALID}.
+     * If the server supports STAR, another possible value is {@link Status#CANCELED}.
      */
     public Status getStatus() {
         return getJSON().get("status").asStatus();
@@ -132,11 +133,17 @@ public class Order extends AcmeJsonResource {
      * Gets the STAR extension's {@link Certificate} if it is available.
      *
      * @since 2.6
+     * @throws IllegalStateException
+     *         if the order is not ready yet. You must finalize the order first, and wait
+     *         for the status to become {@link Status#VALID}. It is also thrown if the
+     *         order has been {@link Status#CANCELED}.
      */
-    public Optional<Certificate> getAutoRenewalCertificate() {
+    public Certificate getAutoRenewalCertificate() {
         return getJSON().get("star-certificate")
-                    .map(Value::asURL)
-                    .map(getLogin()::bindCertificate);
+                .optional()
+                .map(Value::asURL)
+                .map(getLogin()::bindCertificate)
+                .orElseThrow(() -> new IllegalStateException("Order is in an invalid state"));
     }
 
     /**
diff --git a/acme4j-client/src/test/java/org/shredzone/acme4j/OrderTest.java b/acme4j-client/src/test/java/org/shredzone/acme4j/OrderTest.java
index 918c71f8..76d8e488 100644
--- a/acme4j-client/src/test/java/org/shredzone/acme4j/OrderTest.java
+++ b/acme4j-client/src/test/java/org/shredzone/acme4j/OrderTest.java
@@ -218,7 +218,8 @@ public class OrderTest {
                     .isEqualTo("2016-01-08T00:00:00Z");
             softly.assertThat(order.getCertificate().getLocation())
                     .isEqualTo(url("https://example.com/acme/cert/1234"));
-            softly.assertThat(order.getAutoRenewalCertificate()).isEmpty();
+            softly.assertThatIllegalStateException()
+                    .isThrownBy(order::getAutoRenewalCertificate);
             softly.assertThat(order.getFinalizeLocation()).isEqualTo(finalizeUrl);
 
             var auths = order.getAuthorizations();
@@ -310,7 +311,7 @@ public class OrderTest {
         try (var softly = new AutoCloseableSoftAssertions()) {
             softly.assertThatIllegalStateException()
                     .isThrownBy(order::getCertificate);
-            softly.assertThat(order.getAutoRenewalCertificate().orElseThrow().getLocation())
+            softly.assertThat(order.getAutoRenewalCertificate().getLocation())
                     .isEqualTo(url("https://example.com/acme/cert/1234"));
             softly.assertThat(order.isAutoRenewing()).isTrue();
             softly.assertThat(order.getAutoRenewalStartDate().orElseThrow())