diff --git a/acme4j-client/src/site/site.xml b/acme4j-client/src/site/site.xml
index 1c13681e..eab110d3 100644
--- a/acme4j-client/src/site/site.xml
+++ b/acme4j-client/src/site/site.xml
@@ -38,6 +38,6 @@
   <skin>
     <groupId>org.apache.maven.skins</groupId>
     <artifactId>maven-fluido-skin</artifactId>
-    <version>1.6</version>
+    <version>1.7</version>
   </skin>
 </project>
diff --git a/acme4j-client/src/test/java/org/shredzone/acme4j/connector/SessionProviderTest.java b/acme4j-client/src/test/java/org/shredzone/acme4j/connector/SessionProviderTest.java
index b0f160a9..5310499a 100644
--- a/acme4j-client/src/test/java/org/shredzone/acme4j/connector/SessionProviderTest.java
+++ b/acme4j-client/src/test/java/org/shredzone/acme4j/connector/SessionProviderTest.java
@@ -55,8 +55,8 @@ public class SessionProviderTest {
     }
 
     /**
-     * Test that connecting to an acme URI will return an {@link AcmeClient} via
-     * the correct {@link AcmeProvider}, and that the result is cached.
+     * Test that connecting to an acme URI will return an {@link AcmeProvider}, and that
+     * the result is cached.
      */
     @Test
     public void testConnectURI() throws Exception {
diff --git a/acme4j-client/src/test/java/org/shredzone/acme4j/toolbox/AcmeUtilsTest.java b/acme4j-client/src/test/java/org/shredzone/acme4j/toolbox/AcmeUtilsTest.java
index ba4bdb3f..04033c15 100644
--- a/acme4j-client/src/test/java/org/shredzone/acme4j/toolbox/AcmeUtilsTest.java
+++ b/acme4j-client/src/test/java/org/shredzone/acme4j/toolbox/AcmeUtilsTest.java
@@ -41,6 +41,7 @@ import org.jose4j.jwk.PublicJsonWebKey;
 import org.junit.BeforeClass;
 import org.junit.Test;
 import org.shredzone.acme4j.exception.AcmeProtocolException;
+import org.shredzone.acme4j.toolbox.AcmeUtils.PemLabel;
 
 /**
  * Unit tests for {@link AcmeUtils}.
@@ -259,7 +260,7 @@ public class AcmeUtilsTest {
     }
 
     /**
-     * Test that {@link AcmeUtils#writeToPem(byte[], String, Writer)} writes a correct PEM
+     * Test that {@link AcmeUtils#writeToPem(byte[], PemLabel, Writer)} writes a correct PEM
      * file.
      */
     @Test
diff --git a/acme4j-example/pom.xml b/acme4j-example/pom.xml
index 65bb6650..dc50c548 100644
--- a/acme4j-example/pom.xml
+++ b/acme4j-example/pom.xml
@@ -38,7 +38,7 @@
             <plugin>
                 <groupId>org.codehaus.mojo</groupId>
                 <artifactId>exec-maven-plugin</artifactId>
-                <version>1.5.0</version>
+                <version>1.6.0</version>
                 <executions>
                     <execution>
                         <goals>
diff --git a/acme4j-example/src/site/site.xml b/acme4j-example/src/site/site.xml
index 3a6415c7..ed25bba7 100644
--- a/acme4j-example/src/site/site.xml
+++ b/acme4j-example/src/site/site.xml
@@ -37,6 +37,6 @@
   <skin>
     <groupId>org.apache.maven.skins</groupId>
     <artifactId>maven-fluido-skin</artifactId>
-    <version>1.6</version>
+    <version>1.7</version>
   </skin>
 </project>
diff --git a/acme4j-it/src/site/site.xml b/acme4j-it/src/site/site.xml
index 81208233..6f014be8 100644
--- a/acme4j-it/src/site/site.xml
+++ b/acme4j-it/src/site/site.xml
@@ -37,6 +37,6 @@
   <skin>
     <groupId>org.apache.maven.skins</groupId>
     <artifactId>maven-fluido-skin</artifactId>
-    <version>1.6</version>
+    <version>1.7</version>
   </skin>
 </project>
diff --git a/acme4j-utils/src/site/site.xml b/acme4j-utils/src/site/site.xml
index c3416c78..768fb1c5 100644
--- a/acme4j-utils/src/site/site.xml
+++ b/acme4j-utils/src/site/site.xml
@@ -38,6 +38,6 @@
   <skin>
     <groupId>org.apache.maven.skins</groupId>
     <artifactId>maven-fluido-skin</artifactId>
-    <version>1.6</version>
+    <version>1.7</version>
   </skin>
 </project>
diff --git a/pom.xml b/pom.xml
index 5a9691fe..df1530e1 100644
--- a/pom.xml
+++ b/pom.xml
@@ -24,7 +24,7 @@
 
     <name>acme4j</name>
     <description>ACME client for Java</description>
-    <url>http://acme4j.shredzone.org</url>
+    <url>https://acme4j.shredzone.org</url>
     <inceptionYear>2015</inceptionYear>
 
     <licenses>
@@ -51,10 +51,10 @@
     </developers>
 
     <properties>
-        <bouncycastle.version>1.57</bouncycastle.version>
-        <dnsjava.version>2.1.7</dnsjava.version>
-        <httpclient.version>4.5.3</httpclient.version>
-        <jose4j.version>0.6.0</jose4j.version>
+        <bouncycastle.version>1.59</bouncycastle.version>
+        <dnsjava.version>2.1.8</dnsjava.version>
+        <httpclient.version>4.5.5</httpclient.version>
+        <jose4j.version>0.6.3</jose4j.version>
         <nanohttpd.version>2.3.1</nanohttpd.version>
         <slf4j.version>1.7.25</slf4j.version>
         <project.build.sourceEncoding>utf-8</project.build.sourceEncoding>
@@ -73,7 +73,7 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-compiler-plugin</artifactId>
-                <version>3.6.0</version>
+                <version>3.7.0</version>
                 <configuration>
                     <source>1.8</source>
                     <target>1.8</target>
@@ -115,7 +115,7 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-site-plugin</artifactId>
-                <version>3.6</version>
+                <version>3.7</version>
                 <configuration>
                     <outputEncoding>UTF-8</outputEncoding>
                 </configuration>
@@ -123,7 +123,7 @@
                     <dependency>
                         <groupId>org.apache.maven.doxia</groupId>
                         <artifactId>doxia-module-markdown</artifactId>
-                        <version>1.7</version>
+                        <version>1.8</version>
                     </dependency>
                 </dependencies>
             </plugin>
@@ -175,22 +175,17 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-surefire-report-plugin</artifactId>
-                <version>2.19.1</version>
+                <version>2.20.1</version>
             </plugin>
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-javadoc-plugin</artifactId>
-                <version>2.10.4</version>
+                <version>3.0.0</version>
                 <configuration>
-                    <links>
-                        <link>http://docs.oracle.com/javase/8/docs/api/</link>
-                        <link>http://docs.oracle.com/javaee/7/api/</link>
-                        <link>https://www.bouncycastle.org/docs/docs1.5on/</link>
-                        <link>https://www.bouncycastle.org/docs/pkixdocs1.5on/</link>
-                    </links>
                     <charset>UTF-8</charset>
+                    <detectLinks>true</detectLinks>
+                    <doclint>syntax,reference</doclint>
                     <linksource>true</linksource>
-                    <additionalparam>-Xdoclint:syntax,reference</additionalparam>
                 </configuration>
             </plugin>
         </plugins>
diff --git a/src/site/site.xml b/src/site/site.xml
index 7da39bcc..882f7ea6 100644
--- a/src/site/site.xml
+++ b/src/site/site.xml
@@ -57,7 +57,7 @@
   <skin>
     <groupId>org.apache.maven.skins</groupId>
     <artifactId>maven-fluido-skin</artifactId>
-    <version>1.6</version>
+    <version>1.7</version>
   </skin>
 
   <custom>