diff --git a/.circleci/config.yml b/.circleci/config.yml
index c943ca0..07b337b 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -3,54 +3,6 @@ version: 2.1
 workflows:
   tests:
     jobs:
-      - unit-tests:
-          name: java8
-          image: "cimg/openjdk"
-          version: "8.0"
-      - unit-tests:
-          name: java9
-          image: "circleci/openjdk"
-          version: "9"
-      - unit-tests:
-          name: java10
-          image: "circleci/openjdk"
-          version: "10"
-      - unit-tests:
-          name: java11
-          image: "cimg/openjdk"
-          version: "11.0"
-      - unit-tests:
-          name: java12
-          image: "cimg/openjdk"
-          version: "12.0.2"
-      - unit-tests:
-          name: java13
-          image: "cimg/openjdk"
-          version: "13.0.0"
-      - unit-tests:
-          name: java14
-          image: "cimg/openjdk"
-          version: "14.0.0"
-      - unit-tests:
-          name: java15
-          image: "cimg/openjdk"
-          version: "15.0.0"
-      - unit-tests:
-          name: java16
-          image: "cimg/openjdk"
-          version: "16.0.0"
-      - unit-tests:
-          name: java17
-          image: "cimg/openjdk"
-          version: "17.0"
-      - unit-tests:
-          name: java18
-          image: "cimg/openjdk"
-          version: "18.0.1"
-      - unit-tests:
-          name: java19
-          image: "cimg/openjdk"
-          version: "19.0.0"
       - unit-tests:
           name: java21
           image: "cimg/openjdk"
@@ -78,7 +30,7 @@ workflows:
 jobs:
   security-scan:
     docker:
-      - image: cimg/openjdk:11.0
+      - image: cimg/openjdk:21.0
     steps:
       - checkout
       - run:
@@ -118,4 +70,4 @@ jobs:
           command: mvn install -DskipTests=true -Dmaven.javadoc.skip=true -Dgpg.skip=true -B -V
       - run:
           name: Run tests
-          command: mvn test -DforkCount=1 -DreuseForks=false 
+          command: mvn test -DforkCount=1 -DreuseForks=false
diff --git a/CHANGELOG.md b/CHANGELOG.md
index d7540d9..ef5dad0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Changelog
 
+## 2.0.0
+* Update SDK to Java21
+* This fixes a compression issue with Java 21 applications when converting the response body of the requests.
+
 ## 1.13.0
 
 * A new feature (metadata on InboundMessage)
diff --git a/README.md b/README.md
index 45f80da..8f306d6 100644
--- a/README.md
+++ b/README.md
@@ -7,6 +7,8 @@
 [![License](http://img.shields.io/badge/license-MIT-blue.svg?style=flat)](http://www.opensource.org/licenses/MIT)
 [![Maven Central](https://maven-badges.herokuapp.com/maven-central/com.postmarkapp/postmark/badge.svg)](https://maven-badges.herokuapp.com/maven-central/com.postmarkapp/postmark)
 
+:star: :star: **IMPORTANT UPDATE:** :star: :star: As of version 2.0.0, this library requires Java 21. Please ensure your runtime is Java 21 or newer.
+
 :star: :star: **IMPORTANT UPDATE** :star: :star: **As of version 1.9.0, we migrated from groupid ```com.wildbit.java``` to ```com.postmarkapp```.**
 Please update your pom.xml file with new groupid and your imports to use the latest versions of the library. 
 
diff --git a/pom.xml b/pom.xml
index 33bedc8..de901ce 100644
--- a/pom.xml
+++ b/pom.xml
@@ -25,7 +25,7 @@
     <properties>
         <postmark.version>1.13.0</postmark.version>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-        <java.version>1.8</java.version>
+        <java.version>21</java.version>
         <jackson.minimum.version>2.9.7</jackson.minimum.version>
         <jackson.version>2.15.0</jackson.version>
         <junit.jupiter.version>5.8.2</junit.jupiter.version>
@@ -77,7 +77,7 @@
         <dependency>
             <groupId>org.apache.tika</groupId>
             <artifactId>tika-core</artifactId>
-            <version>2.9.4</version>
+            <version>3.2.3</version>
         </dependency>
 
 
@@ -107,7 +107,7 @@
         <dependency>
             <groupId>org.mockito</groupId>
             <artifactId>mockito-core</artifactId>
-            <version>2.11.0</version>
+            <version>4.110</version>
             <scope>test</scope>
         </dependency>
     </dependencies>
@@ -120,7 +120,7 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-compiler-plugin</artifactId>
-                <version>3.8.1</version>
+                <version>3.13.0</version>
                 <configuration>
                     <source>${java.version}</source>
                     <target>${java.version}</target>
@@ -130,8 +130,7 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-surefire-plugin</artifactId>
-                <version>2.22.2</version>
-                <!-- workaround line to make test work on java10 https://maven.apache.org/surefire/maven-surefire-plugin/examples/class-loading.html -->
+                <version>3.2.5</version>
                 <configuration>
                     <useSystemClassLoader>false</useSystemClassLoader>
                     <forkCount>1</forkCount>
@@ -142,7 +141,7 @@
             <plugin>
                 <groupId>org.apache.maven.plugins</groupId>
                 <artifactId>maven-failsafe-plugin</artifactId>
-                <version>2.22.2</version>
+                <version>3.2.5</version>
             </plugin>
         </plugins>
 
@@ -202,7 +201,7 @@
                 <plugin>
                     <groupId>org.apache.maven.plugins</groupId>
                     <artifactId>maven-javadoc-plugin</artifactId>
-                    <version>2.9.1</version>
+                    <version>3.6.3</version>
                     <executions>
                         <execution>
                             <id>attach-javadocs</id>