diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index dd5b8c25a..7c93a84e7 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -118,7 +118,7 @@ jobs:
     strategy:
       matrix:
         java: [ 11, 17 ]
-        junit-version: [ '5.8.2' ]
+        junit-version: [ '5.9.0' ]
         modular: [true, false]
         os: [ubuntu, macos, windows]
     name: with Java ${{ matrix.java }}, JUnit ${{ matrix.junit-version }}, Modular ${{ matrix.modular }} on ${{ matrix.os }}
@@ -147,7 +147,7 @@ jobs:
     timeout-minutes: 15
     strategy:
       matrix:
-        junit-version: [ '5.8.2' ]
+        junit-version: [ '5.9.0' ]
         modular: [true, false]
         os: [ubuntu, macos, windows]
     name: Experimental build with newest JDK early-access build and Gradle release candidate
diff --git a/gradle.properties b/gradle.properties
index 038de1dca..c1b4a6a55 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -1,4 +1,4 @@
-junitVersion=5.8.2
+junitVersion=5.9.0
 
 # Ensure sufficient heap size, especially for Sonar.
 org.gradle.jvmargs=-Xmx8g
diff --git a/src/demo/java/org/junitpioneer/jupiter/EnvironmentVariablesExtensionDemo.java b/src/demo/java/org/junitpioneer/jupiter/EnvironmentVariablesExtensionDemo.java
index adea8afd8..f94b48779 100644
--- a/src/demo/java/org/junitpioneer/jupiter/EnvironmentVariablesExtensionDemo.java
+++ b/src/demo/java/org/junitpioneer/jupiter/EnvironmentVariablesExtensionDemo.java
@@ -13,7 +13,10 @@
 import static org.assertj.core.api.Assertions.assertThat;
 
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.condition.EnabledForJreRange;
+import org.junit.jupiter.api.condition.JRE;
 
+@EnabledForJreRange(max = JRE.JAVA_16, disabledReason = "See: https://github.com/junit-pioneer/junit-pioneer/issues/509")
 public class EnvironmentVariablesExtensionDemo {
 
 	// tag::environment_clear_simple[]
diff --git a/src/test/java/org/junitpioneer/internal/TestExtensionContext.java b/src/test/java/org/junitpioneer/internal/TestExtensionContext.java
index 50961e65b..2d3122185 100644
--- a/src/test/java/org/junitpioneer/internal/TestExtensionContext.java
+++ b/src/test/java/org/junitpioneer/internal/TestExtensionContext.java
@@ -18,6 +18,7 @@
 import java.util.function.Function;
 
 import org.junit.jupiter.api.TestInstance;
+import org.junit.jupiter.api.extension.ExecutableInvoker;
 import org.junit.jupiter.api.extension.ExtensionContext;
 import org.junit.jupiter.api.extension.TestInstances;
 import org.junit.jupiter.api.parallel.ExecutionMode;
@@ -42,11 +43,16 @@ public TestExtensionContext(Class<?> testClass, Method testMethod) {
 		this.testMethod = testMethod;
 	}
 
-	// @Override once we baseline against 5.8
+	@Override
 	public ExecutionMode getExecutionMode() {
 		throw NOT_SUPPORTED_IN_TEST_CONTEXT;
 	}
 
+	@Override
+	public ExecutableInvoker getExecutableInvoker() {
+		throw NOT_SUPPORTED_IN_TEST_CONTEXT;
+	}
+
 	@Override
 	public Optional<Class<?>> getTestClass() {
 		return Optional.of(testClass);
diff --git a/src/test/java/org/junitpioneer/jupiter/AbstractEntryBasedExtensionTests.java b/src/test/java/org/junitpioneer/jupiter/AbstractEntryBasedExtensionTests.java
index 1957fc7cc..b4b97c351 100644
--- a/src/test/java/org/junitpioneer/jupiter/AbstractEntryBasedExtensionTests.java
+++ b/src/test/java/org/junitpioneer/jupiter/AbstractEntryBasedExtensionTests.java
@@ -16,8 +16,11 @@
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.condition.EnabledForJreRange;
+import org.junit.jupiter.api.condition.JRE;
 import org.junitpioneer.testkit.PioneerTestKit;
 
+@EnabledForJreRange(max = JRE.JAVA_16, disabledReason = "See: https://github.com/junit-pioneer/junit-pioneer/issues/509")
 @DisplayName("Abstract entry-based extension")
 @WritesEnvironmentVariable
 @WritesSystemProperty
diff --git a/src/test/java/org/junitpioneer/jupiter/cartesian/CartesianTestExtensionTests.java b/src/test/java/org/junitpioneer/jupiter/cartesian/CartesianTestExtensionTests.java
index 66c81e4ec..86fb2d4f1 100644
--- a/src/test/java/org/junitpioneer/jupiter/cartesian/CartesianTestExtensionTests.java
+++ b/src/test/java/org/junitpioneer/jupiter/cartesian/CartesianTestExtensionTests.java
@@ -576,7 +576,7 @@ void nonEnumParameterWithCartesianEnumSourceOmittedType() {
 					.hasSingleFailedContainer()
 					.withExceptionInstanceOf(ExtensionConfigurationException.class)
 					.hasMessageContaining("Could not provide arguments")
-					.getCause()
+					.cause()
 					.isInstanceOf(PreconditionViolationException.class)
 					.hasMessageContaining("Parameter of type %s must reference an Enum type", int.class);
 		}
diff --git a/src/test/java/org/junitpioneer/jupiter/json/JsonSourceArgumentsProviderTests.java b/src/test/java/org/junitpioneer/jupiter/json/JsonSourceArgumentsProviderTests.java
index 25668d10c..2e1e750fb 100644
--- a/src/test/java/org/junitpioneer/jupiter/json/JsonSourceArgumentsProviderTests.java
+++ b/src/test/java/org/junitpioneer/jupiter/json/JsonSourceArgumentsProviderTests.java
@@ -214,7 +214,7 @@ void noValuesCartesian() {
 			assertThat(results)
 					.hasSingleFailedContainer()
 					.withExceptionInstanceOf(ExtensionConfigurationException.class)
-					.getCause()
+					.cause()
 					.isInstanceOf(PreconditionViolationException.class)
 					.hasMessage("value must not be empty");
 		}