diff --git a/apt-test-generator/pom.xml b/apt-test-generator/pom.xml
index 05243f530f..10648dfc1a 100644
--- a/apt-test-generator/pom.xml
+++ b/apt-test-generator/pom.xml
@@ -36,7 +36,7 @@
     <dependency>
       <groupId>com.github.jknack</groupId>
       <artifactId>handlebars</artifactId>
-      <version>4.1.2</version>
+      <version>4.3.0</version>
     </dependency>
 
     <dependency>
@@ -48,9 +48,16 @@
     <dependency>
       <groupId>com.google.testing.compile</groupId>
       <artifactId>compile-testing</artifactId>
-      <version>0.18</version>
+      <version>0.19</version>
       <scope>test</scope>
     </dependency>
+    <dependency>
+      <groupId>org.slf4j</groupId>
+      <artifactId>slf4j-jdk14</artifactId>
+      <version>1.7.25</version>
+      <scope>test</scope>
+    </dependency>
+
     <dependency>
       <groupId>com.google.guava</groupId>
       <artifactId>guava</artifactId>
@@ -171,4 +178,18 @@
       </plugin>
     </plugins>
   </build>
+
+  <profiles>
+    <profile>
+      <id>active-on-jdk-9</id>
+      <activation>
+        <jdk>[9,)</jdk>
+      </activation>
+
+      <properties>
+        <maven-surefire-plugin.version>3.0.0-M5</maven-surefire-plugin.version>
+        <jvm.options>--add-opens jdk.compiler/com.sun.tools.javac.api=ALL-UNNAMED</jvm.options>
+      </properties>
+    </profile>
+  </profiles>
 </project>
diff --git a/json/pom.xml b/json/pom.xml
index d135891233..beea4d8088 100644
--- a/json/pom.xml
+++ b/json/pom.xml
@@ -29,7 +29,6 @@
 
   <properties>
     <main.basedir>${project.basedir}/..</main.basedir>
-    <mockito.version>1.10.19</mockito.version>
   </properties>
 
   <dependencies>
@@ -48,7 +47,7 @@
     </dependency>
     <dependency>
       <groupId>org.mockito</groupId>
-      <artifactId>mockito-all</artifactId>
+      <artifactId>mockito-core</artifactId>
       <version>${mockito.version}</version>
       <scope>test</scope>
     </dependency>
diff --git a/json/src/test/java/feign/json/JsonDecoderTest.java b/json/src/test/java/feign/json/JsonDecoderTest.java
index a90a0062f5..05eb7ead0c 100644
--- a/json/src/test/java/feign/json/JsonDecoderTest.java
+++ b/json/src/test/java/feign/json/JsonDecoderTest.java
@@ -13,23 +13,26 @@
  */
 package feign.json;
 
+import static feign.Util.UTF_8;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertThrows;
+import static org.junit.Assert.assertTrue;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
 import feign.Request;
 import feign.Response;
 import feign.codec.DecodeException;
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.util.Collections;
+import java.util.Date;
 import org.json.JSONArray;
 import org.json.JSONException;
 import org.json.JSONObject;
 import org.junit.BeforeClass;
 import org.junit.Test;
-import java.io.IOException;
-import java.nio.charset.StandardCharsets;
-import java.util.Collections;
-import java.util.Date;
-import static feign.Util.UTF_8;
-import static org.junit.Assert.*;
-import static org.mockito.Matchers.any;
-import static org.mockito.Mockito.mock;
-import static org.mockito.Mockito.when;
 
 public class JsonDecoderTest {
 
diff --git a/pom.xml b/pom.xml
index 7c979e08af..ffb36fac46 100644
--- a/pom.xml
+++ b/pom.xml
@@ -69,8 +69,8 @@
     <main.signature.artifact>java18</main.signature.artifact>
 
     <!-- default bytecode version for src/test -->
-    <maven.compiler.source>1.8</maven.compiler.source>
-    <maven.compiler.target>1.8</maven.compiler.target>
+    <maven.compiler.source>${main.java.version}</maven.compiler.source>
+    <maven.compiler.target>${main.java.version}</maven.compiler.target>
 
     <main.basedir>${project.basedir}</main.basedir>
 
@@ -86,6 +86,7 @@
     <jackson.version>2.12.5</jackson.version>
     <assertj.version>3.10.0</assertj.version>
     <hamcrest.version>2.2</hamcrest.version>
+    <mockito.version>4.0.0</mockito.version>
 
     <animal-sniffer-maven-plugin.version>1.17</animal-sniffer-maven-plugin.version>
     <maven-compiler-plugin.version>3.8.0</maven-compiler-plugin.version>
@@ -95,7 +96,7 @@
     <license-maven-plugin.version>3.0</license-maven-plugin.version>
     <maven-jar-plugin.version>3.1.0</maven-jar-plugin.version>
     <maven-release-plugin.version>2.5.3</maven-release-plugin.version>
-    <maven-bundle-plugin.version>4.0.0</maven-bundle-plugin.version>
+    <maven-bundle-plugin.version>5.1.2</maven-bundle-plugin.version>
     <centralsync-maven-plugin.version>0.1.0</centralsync-maven-plugin.version>
     <maven-surefire-plugin.version>2.22.0</maven-surefire-plugin.version>
     <bom-generator.version>0.14.3</bom-generator.version>
@@ -445,6 +446,10 @@
       <plugin>
         <artifactId>maven-compiler-plugin</artifactId>
         <inherited>true</inherited>
+        <configuration>
+          <source>${main.java.version}</source>
+          <target>${main.java.version}</target>
+        </configuration>
         <executions>
           <!-- Ensure main source tree compiles to Java ${main.java.version} bytecode. -->
           <execution>
@@ -459,7 +464,7 @@
             </configuration>
           </execution>
           <execution>
-            <id>default-test-compile</id>
+            <id>default-testCompile</id>
             <phase>test-compile</phase>
             <goals>
               <goal>testCompile</goal>
diff --git a/reactive/pom.xml b/reactive/pom.xml
index 929cbec0bb..5a2773b338 100644
--- a/reactive/pom.xml
+++ b/reactive/pom.xml
@@ -31,7 +31,6 @@
     <reactor.version>3.3.0.RELEASE</reactor.version>
     <reactive.streams.version>1.0.3</reactive.streams.version>
     <reactivex.version>2.2.14</reactivex.version>
-    <mockito.version>1.9.5</mockito.version>
   </properties>
 
   <dependencies>
@@ -61,7 +60,7 @@
     </dependency>
     <dependency>
       <groupId>org.mockito</groupId>
-      <artifactId>mockito-all</artifactId>
+      <artifactId>mockito-core</artifactId>
       <version>${mockito.version}</version>
       <scope>test</scope>
     </dependency>
diff --git a/reactive/src/test/java/feign/reactive/ReactiveFeignIntegrationTest.java b/reactive/src/test/java/feign/reactive/ReactiveFeignIntegrationTest.java
index 613ca03d2c..347358bd00 100644
--- a/reactive/src/test/java/feign/reactive/ReactiveFeignIntegrationTest.java
+++ b/reactive/src/test/java/feign/reactive/ReactiveFeignIntegrationTest.java
@@ -1,5 +1,5 @@
 /**
- * Copyright 2012-2020 The Feign Authors
+ * Copyright 2012-2021 The Feign Authors
  *
  * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
  * in compliance with the License. You may obtain a copy of the License at
@@ -14,9 +14,9 @@
 package feign.reactive;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.ArgumentMatchers.anyString;
 import static org.mockito.BDDMockito.given;
-import static org.mockito.Matchers.any;
-import static org.mockito.Matchers.anyString;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.spy;
 import static org.mockito.Mockito.times;
diff --git a/reactive/src/test/java/feign/reactive/ReactiveInvocationHandlerTest.java b/reactive/src/test/java/feign/reactive/ReactiveInvocationHandlerTest.java
index 517d227d9c..2f3b42a2ac 100644
--- a/reactive/src/test/java/feign/reactive/ReactiveInvocationHandlerTest.java
+++ b/reactive/src/test/java/feign/reactive/ReactiveInvocationHandlerTest.java
@@ -1,5 +1,5 @@
 /**
- * Copyright 2012-2020 The Feign Authors
+ * Copyright 2012-2021 The Feign Authors
  *
  * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
  * in compliance with the License. You may obtain a copy of the License at
@@ -14,11 +14,11 @@
 package feign.reactive;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.BDDMockito.given;
-import static org.mockito.Matchers.any;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
-import static org.mockito.Mockito.verifyZeroInteractions;
+import static org.mockito.Mockito.verifyNoInteractions;
 import feign.InvocationHandlerFactory.MethodHandler;
 import feign.RequestLine;
 import feign.Target;
@@ -30,7 +30,7 @@
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.mockito.Mock;
-import org.mockito.runners.MockitoJUnitRunner;
+import org.mockito.junit.MockitoJUnitRunner;
 import reactor.core.publisher.Mono;
 import reactor.core.scheduler.Schedulers;
 import reactor.test.StepVerifier;
@@ -60,7 +60,7 @@ public void invokeOnSubscribeReactor() throws Throwable {
 
     Object result = handler.invoke(method, this.methodHandler, new Object[] {});
     assertThat(result).isInstanceOf(Mono.class);
-    verifyZeroInteractions(this.methodHandler);
+    verifyNoInteractions(this.methodHandler);
 
     /* subscribe and execute the method */
     StepVerifier.create((Mono) result)
@@ -78,7 +78,7 @@ public void invokeOnSubscribeEmptyReactor() throws Throwable {
 
     Object result = handler.invoke(method, this.methodHandler, new Object[] {});
     assertThat(result).isInstanceOf(Mono.class);
-    verifyZeroInteractions(this.methodHandler);
+    verifyNoInteractions(this.methodHandler);
 
     /* subscribe and execute the method */
     StepVerifier.create((Mono) result)
@@ -95,7 +95,7 @@ public void invokeFailureReactor() throws Throwable {
 
     Object result = handler.invoke(this.method, this.methodHandler, new Object[] {});
     assertThat(result).isInstanceOf(Mono.class);
-    verifyZeroInteractions(this.methodHandler);
+    verifyNoInteractions(this.methodHandler);
 
     /* subscribe and execute the method, should result in an error */
     StepVerifier.create((Mono) result)
@@ -115,7 +115,7 @@ public void invokeOnSubscribeRxJava() throws Throwable {
 
     Object result = handler.invoke(this.method, this.methodHandler, new Object[] {});
     assertThat(result).isInstanceOf(Flowable.class);
-    verifyZeroInteractions(this.methodHandler);
+    verifyNoInteractions(this.methodHandler);
 
     /* subscribe and execute the method */
     StepVerifier.create((Flowable) result)
@@ -135,7 +135,7 @@ public void invokeOnSubscribeEmptyRxJava() throws Throwable {
 
     Object result = handler.invoke(this.method, this.methodHandler, new Object[] {});
     assertThat(result).isInstanceOf(Flowable.class);
-    verifyZeroInteractions(this.methodHandler);
+    verifyNoInteractions(this.methodHandler);
 
     /* subscribe and execute the method */
     StepVerifier.create((Flowable) result)
@@ -154,7 +154,7 @@ public void invokeFailureRxJava() throws Throwable {
 
     Object result = handler.invoke(this.method, this.methodHandler, new Object[] {});
     assertThat(result).isInstanceOf(Flowable.class);
-    verifyZeroInteractions(this.methodHandler);
+    verifyNoInteractions(this.methodHandler);
 
     /* subscribe and execute the method */
     StepVerifier.create((Flowable) result)