diff --git a/takari-plugin-testing-its/src/test/java/io/takari/maven/testing/test/IntegrationTest.java b/takari-plugin-testing-its/src/test/java/io/takari/maven/testing/test/IntegrationTest.java
index 4a57dad..dc73196 100644
--- a/takari-plugin-testing-its/src/test/java/io/takari/maven/testing/test/IntegrationTest.java
+++ b/takari-plugin-testing-its/src/test/java/io/takari/maven/testing/test/IntegrationTest.java
@@ -7,6 +7,7 @@
 import java.io.IOException;
 import java.io.OutputStreamWriter;
 import java.io.Writer;
+import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.List;
 import org.junit.Assume;
@@ -63,7 +64,7 @@ public void testBasic() throws Exception {
     }
 
     private void write(File file, String string) throws IOException {
-        try (Writer w = new OutputStreamWriter(new FileOutputStream(file), "UTF-8")) {
+        try (Writer w = new OutputStreamWriter(new FileOutputStream(file), StandardCharsets.UTF_8)) {
             w.write(string);
         }
     }
diff --git a/takari-plugin-testing/src/main/java/io/takari/maven/testing/Maven30xRuntime.java b/takari-plugin-testing/src/main/java/io/takari/maven/testing/Maven30xRuntime.java
index f37d04e..712560b 100644
--- a/takari-plugin-testing/src/main/java/io/takari/maven/testing/Maven30xRuntime.java
+++ b/takari-plugin-testing/src/main/java/io/takari/maven/testing/Maven30xRuntime.java
@@ -42,6 +42,7 @@
 import java.lang.reflect.Constructor;
 import java.net.MalformedURLException;
 import java.net.URL;
+import java.nio.charset.StandardCharsets;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.Enumeration;
@@ -234,7 +235,8 @@ protected ProjectBuildingRequest getProjectBuildingRequest(MavenExecutionRequest
 
     protected File getPomFile(File pom) throws IOException {
         if (!pom.exists()) {
-            try (BufferedWriter w = new BufferedWriter(new OutputStreamWriter(new FileOutputStream(pom), "UTF-8"))) {
+            try (BufferedWriter w =
+                    new BufferedWriter(new OutputStreamWriter(new FileOutputStream(pom), StandardCharsets.UTF_8))) {
                 w.write("<?xml version='1.0' encoding='UTF-8'?>\n");
                 w.write("<project>\n");
                 w.write("<modelVersion>4.0.0</modelVersion>\n");
diff --git a/takari-plugin-testing/src/main/java/io/takari/maven/testing/executor/Embedded3xLauncher.java b/takari-plugin-testing/src/main/java/io/takari/maven/testing/executor/Embedded3xLauncher.java
index 5cc309d..2adab65 100644
--- a/takari-plugin-testing/src/main/java/io/takari/maven/testing/executor/Embedded3xLauncher.java
+++ b/takari-plugin-testing/src/main/java/io/takari/maven/testing/executor/Embedded3xLauncher.java
@@ -41,6 +41,7 @@
 import java.net.MalformedURLException;
 import java.net.URL;
 import java.net.URLClassLoader;
+import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
@@ -117,7 +118,7 @@ public void addLoadURL(URL url) {
         }
 
         public void store(OutputStream os) throws IOException {
-            BufferedWriter out = new BufferedWriter(new OutputStreamWriter(os, "UTF-8")); // $NON-NLS-1$
+            BufferedWriter out = new BufferedWriter(new OutputStreamWriter(os, StandardCharsets.UTF_8)); // $NON-NLS-1$
             out.write(String.format("main is %s from %s\n", mainType, mainRealm));
             for (Map.Entry<String, List<String>> realm : realms.entrySet()) {
                 out.write(String.format("[%s]\n", realm.getKey()));
diff --git a/takari-plugin-testing/src/main/java/io/takari/maven/testing/executor/junit/MavenInstallationsTestExtension.java b/takari-plugin-testing/src/main/java/io/takari/maven/testing/executor/junit/MavenInstallationsTestExtension.java
index 6236447..4da0628 100644
--- a/takari-plugin-testing/src/main/java/io/takari/maven/testing/executor/junit/MavenInstallationsTestExtension.java
+++ b/takari-plugin-testing/src/main/java/io/takari/maven/testing/executor/junit/MavenInstallationsTestExtension.java
@@ -41,7 +41,7 @@ public boolean supportsTestTemplate(ExtensionContext context) {
     public Stream<TestTemplateInvocationContext> provideTestTemplateInvocationContexts(ExtensionContext context) {
         String displayName = context.getDisplayName();
         String[] installations = context.getTestClass()
-                .get()
+                .orElseThrow()
                 .getAnnotation(MavenInstallations.class)
                 .value();
         return Arrays.stream(installations)
diff --git a/takari-plugin-testing/src/main/java/io/takari/maven/testing/executor/junit/MavenVersionsTestExtension.java b/takari-plugin-testing/src/main/java/io/takari/maven/testing/executor/junit/MavenVersionsTestExtension.java
index 904445b..3c06219 100644
--- a/takari-plugin-testing/src/main/java/io/takari/maven/testing/executor/junit/MavenVersionsTestExtension.java
+++ b/takari-plugin-testing/src/main/java/io/takari/maven/testing/executor/junit/MavenVersionsTestExtension.java
@@ -44,8 +44,10 @@ public boolean supportsTestTemplate(ExtensionContext context) {
     @Override
     public Stream<TestTemplateInvocationContext> provideTestTemplateInvocationContexts(ExtensionContext context) {
         String displayName = context.getDisplayName();
-        String[] versions =
-                context.getTestClass().get().getAnnotation(MavenVersions.class).value();
+        String[] versions = context.getTestClass()
+                .orElseThrow()
+                .getAnnotation(MavenVersions.class)
+                .value();
         List<TestTemplateInvocationContext> contexts = new ArrayList<>();
         List<Throwable> errors = new ArrayList<>();