diff --git a/services/git-bridge/Dockerfile b/services/git-bridge/Dockerfile
index f7407b09ab..de8a3edb51 100644
--- a/services/git-bridge/Dockerfile
+++ b/services/git-bridge/Dockerfile
@@ -1,6 +1,6 @@
 # Dockerfile for git-bridge
 
-FROM maven:3-amazoncorretto-11-debian as base
+FROM maven:3-amazoncorretto-21-debian as base
 
 RUN apt-get update && apt-get install -y make git sqlite3 \
  && rm -rf /var/lib/apt/lists
@@ -23,7 +23,7 @@ RUN make package \
       -name 'writelatex-git-bridge*jar-with-dependencies.jar' \
       -exec mv {} /git-bridge.jar \;
 
-FROM amazoncorretto:11-alpine
+FROM amazoncorretto:21-alpine
 
 RUN apk add --update --no-cache bash git sqlite procps htop net-tools jemalloc
 
diff --git a/services/git-bridge/pom.xml b/services/git-bridge/pom.xml
index 16fba4a94e..809676d769 100644
--- a/services/git-bridge/pom.xml
+++ b/services/git-bridge/pom.xml
@@ -8,9 +8,9 @@
     <artifactId>writelatex-git-bridge</artifactId>
     <version>1.0-SNAPSHOT</version>
     <properties>
-        <java.version>1.8</java.version>
+        <java.version>21</java.version>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
-        <maven.compiler.plugin.version>3.7.0</maven.compiler.plugin.version>
+        <maven.compiler.plugin.version>3.13.0</maven.compiler.plugin.version>
         <maven.surefire.plugin.version>2.12.4</maven.surefire.plugin.version>
         <maven.assembly.plugin.version>3.1.0</maven.assembly.plugin.version>
         <fmt.plugin.version>2.23</fmt.plugin.version>
@@ -27,7 +27,7 @@
         <commons.lang3.version>3.12.0</commons.lang3.version>
         <logback.classic.version>1.2.3</logback.classic.version>
         <mockserver.version>5.12.0</mockserver.version>
-        <mockito.version>3.11.1</mockito.version>
+        <mockito.version>5.12.0</mockito.version>
         <aws.java.sdk.version>1.11.274</aws.java.sdk.version>
         <jakarta.xml.bind.api.version>${jaxb.runtime.version}</jakarta.xml.bind.api.version>
         <jaxb.runtime.version>2.3.2</jaxb.runtime.version>
@@ -35,6 +35,7 @@
         <commons.io.version>2.10.0</commons.io.version>
         <commons.compress.version>1.24.0</commons.compress.version>
         <simpleclient.version>0.10.0</simpleclient.version>
+        <bouncycastle.crypto.version>1.70</bouncycastle.crypto.version>
     </properties>
     <build>
         <plugins>
@@ -45,6 +46,7 @@
                 <configuration>
                     <source>${java.version}</source>
                     <target>${java.version}</target>
+                    <release>${java.version}</release>
                 </configuration>
             </plugin>
             <!-- Workaround, test loader crashes without this configuration option -->
@@ -256,5 +258,18 @@
             <artifactId>simpleclient_servlet</artifactId>
             <version>${simpleclient.version}</version>
         </dependency>
+        <!-- Require by MockServerClient to load 'sun.security.x509' / 'sun.security.util' -->
+        <dependency>
+            <groupId>org.bouncycastle</groupId>
+            <artifactId>bcprov-jdk15on</artifactId>
+            <version>${bouncycastle.crypto.version}</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+           <groupId>org.bouncycastle</groupId>
+            <artifactId>bcpkix-jdk15on</artifactId>
+            <version>${bouncycastle.crypto.version}</version>
+            <scope>test</scope>
+        </dependency>
     </dependencies>
 </project>
diff --git a/services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/util/DeletingFileInputStream.java b/services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/util/DeletingFileInputStream.java
index 6589a42110..a19218a762 100644
--- a/services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/util/DeletingFileInputStream.java
+++ b/services/git-bridge/src/main/java/uk/ac/ic/wlgitbridge/util/DeletingFileInputStream.java
@@ -43,7 +43,7 @@ public class DeletingFileInputStream extends FileInputStream {
    * We shouldn't rely on this for correctness!
    */
   @Override
-  protected void finalize() throws IOException {
+  protected void finalize() throws Throwable {
     try {
       super.finalize();
     } finally {
diff --git a/services/git-bridge/src/test/java/uk/ac/ic/wlgitbridge/bridge/BridgeTest.java b/services/git-bridge/src/test/java/uk/ac/ic/wlgitbridge/bridge/BridgeTest.java
index 48899b3a16..f749dea357 100644
--- a/services/git-bridge/src/test/java/uk/ac/ic/wlgitbridge/bridge/BridgeTest.java
+++ b/services/git-bridge/src/test/java/uk/ac/ic/wlgitbridge/bridge/BridgeTest.java
@@ -1,8 +1,5 @@
 package uk.ac.ic.wlgitbridge.bridge;
 
-import static org.mockito.Matchers.any;
-import static org.mockito.Matchers.anyInt;
-import static org.mockito.Matchers.eq;
 import static org.mockito.Mockito.*;
 
 import java.io.IOException;
diff --git a/services/git-bridge/src/test/java/uk/ac/ic/wlgitbridge/bridge/resource/UrlResourceCacheTest.java b/services/git-bridge/src/test/java/uk/ac/ic/wlgitbridge/bridge/resource/UrlResourceCacheTest.java
index 862662696c..f49822a7df 100644
--- a/services/git-bridge/src/test/java/uk/ac/ic/wlgitbridge/bridge/resource/UrlResourceCacheTest.java
+++ b/services/git-bridge/src/test/java/uk/ac/ic/wlgitbridge/bridge/resource/UrlResourceCacheTest.java
@@ -1,6 +1,6 @@
 package uk.ac.ic.wlgitbridge.bridge.resource;
 
-import static org.mockito.Matchers.any;
+import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;