diff --git a/acme4j-client/src/main/java/org/shredzone/acme4j/challenge/TokenChallenge.java b/acme4j-client/src/main/java/org/shredzone/acme4j/challenge/TokenChallenge.java
index 66fae937..12dda0b1 100644
--- a/acme4j-client/src/main/java/org/shredzone/acme4j/challenge/TokenChallenge.java
+++ b/acme4j-client/src/main/java/org/shredzone/acme4j/challenge/TokenChallenge.java
@@ -22,6 +22,7 @@ import org.jose4j.lang.JoseException;
 import org.shredzone.acme4j.Login;
 import org.shredzone.acme4j.exception.AcmeProtocolException;
 import org.shredzone.acme4j.toolbox.JSON;
+import org.shredzone.acme4j.toolbox.JSONBuilder;
 
 /**
  * An extension of {@link Challenge} that handles challenges with a {@code token} and
@@ -31,6 +32,7 @@ public class TokenChallenge extends Challenge {
     private static final long serialVersionUID = 1634133407432681800L;
 
     protected static final String KEY_TOKEN = "token";
+    protected static final String KEY_KEY_AUTHORIZATION = "keyAuthorization";
 
     /**
      * Creates a new generic {@link TokenChallenge} object.
@@ -44,6 +46,12 @@ public class TokenChallenge extends Challenge {
         super(login, data);
     }
 
+    @Override
+    protected void prepareResponse(JSONBuilder response) {
+        super.prepareResponse(response);
+        response.put(KEY_KEY_AUTHORIZATION, getAuthorization());
+    }
+
     /**
      * Gets the token.
      */
diff --git a/acme4j-client/src/test/java/org/shredzone/acme4j/challenge/DnsChallengeTest.java b/acme4j-client/src/test/java/org/shredzone/acme4j/challenge/DnsChallengeTest.java
index 9dd1daef..fcaf174d 100644
--- a/acme4j-client/src/test/java/org/shredzone/acme4j/challenge/DnsChallengeTest.java
+++ b/acme4j-client/src/test/java/org/shredzone/acme4j/challenge/DnsChallengeTest.java
@@ -30,6 +30,8 @@ import org.shredzone.acme4j.toolbox.TestUtils;
  * Unit tests for {@link Dns01Challenge}.
  */
 public class DnsChallengeTest {
+    private static final String KEY_AUTHORIZATION =
+            "pNvmJivs0WCko2suV7fhe-59oFqyYx_yB7tx6kIMAyE.HnWjTDnyqlCrm6tZ-6wX-TrEXgRdeNu9G71gqxSO6o0";
 
     private Login login = TestUtils.login();
 
@@ -43,12 +45,12 @@ public class DnsChallengeTest {
         assertThat(challenge.getType(), is(Dns01Challenge.TYPE));
         assertThat(challenge.getStatus(), is(Status.PENDING));
         assertThat(challenge.getDigest(), is("rzMmotrIgsithyBYc0vgiLUEEKYx0WetQRgEF2JIozA"));
-        assertThat(challenge.getAuthorization(), is("pNvmJivs0WCko2suV7fhe-59oFqyYx_yB7tx6kIMAyE.HnWjTDnyqlCrm6tZ-6wX-TrEXgRdeNu9G71gqxSO6o0"));
 
         JSONBuilder response = new JSONBuilder();
         challenge.prepareResponse(response);
 
-        assertThat(response.toString(), sameJSONAs("{}").allowingExtraUnexpectedFields());
+        assertThat(response.toString(), sameJSONAs("{\"keyAuthorization\"=\""
+            + KEY_AUTHORIZATION + "\"}").allowingExtraUnexpectedFields());
     }
 
 }
diff --git a/acme4j-client/src/test/java/org/shredzone/acme4j/challenge/HttpChallengeTest.java b/acme4j-client/src/test/java/org/shredzone/acme4j/challenge/HttpChallengeTest.java
index 714309fd..2773d2a9 100644
--- a/acme4j-client/src/test/java/org/shredzone/acme4j/challenge/HttpChallengeTest.java
+++ b/acme4j-client/src/test/java/org/shredzone/acme4j/challenge/HttpChallengeTest.java
@@ -53,7 +53,8 @@ public class HttpChallengeTest {
         JSONBuilder response = new JSONBuilder();
         challenge.prepareResponse(response);
 
-        assertThat(response.toString(), sameJSONAs("{}").allowingExtraUnexpectedFields());
+        assertThat(response.toString(), sameJSONAs("{\"keyAuthorization\"=\""
+            + KEY_AUTHORIZATION + "\"}").allowingExtraUnexpectedFields());
     }
 
     /**
diff --git a/acme4j-client/src/test/resources/json/triggerHttpChallengeRequest.json b/acme4j-client/src/test/resources/json/triggerHttpChallengeRequest.json
index 2c63c085..8ecbc882 100644
--- a/acme4j-client/src/test/resources/json/triggerHttpChallengeRequest.json
+++ b/acme4j-client/src/test/resources/json/triggerHttpChallengeRequest.json
@@ -1,2 +1,3 @@
 {
+  "keyAuthorization": "IlirfxKKXAsHtmzK29Pj8A.HnWjTDnyqlCrm6tZ-6wX-TrEXgRdeNu9G71gqxSO6o0"
 }
diff --git a/acme4j-client/src/test/resources/json/triggerHttpChallengeResponse.json b/acme4j-client/src/test/resources/json/triggerHttpChallengeResponse.json
index 42ce743d..6845afe5 100644
--- a/acme4j-client/src/test/resources/json/triggerHttpChallengeResponse.json
+++ b/acme4j-client/src/test/resources/json/triggerHttpChallengeResponse.json
@@ -2,5 +2,6 @@
   "type": "http-01",
   "status": "pending",
   "url": "https://example.com/acme/some-location",
-  "token": "IlirfxKKXAsHtmzK29Pj8A"
+  "token": "IlirfxKKXAsHtmzK29Pj8A",
+  "keyAuthorization": "XbmEGDDc2AMDArHLt5x7GxZfIRv0aScknUKlyf5S4KU.KMH_h8aGAKlY3VQqBUczm1cfo9kaovivy59rSY1xZ0E"
 }