diff --git a/spring-cloud-openfeign-core/src/test/java/org/springframework/cloud/openfeign/FeignClientOverrideDefaultsTests.java b/spring-cloud-openfeign-core/src/test/java/org/springframework/cloud/openfeign/FeignClientOverrideDefaultsTests.java
index 595e5566..98aedc86 100644
--- a/spring-cloud-openfeign-core/src/test/java/org/springframework/cloud/openfeign/FeignClientOverrideDefaultsTests.java
+++ b/spring-cloud-openfeign-core/src/test/java/org/springframework/cloud/openfeign/FeignClientOverrideDefaultsTests.java
@@ -24,7 +24,6 @@ import feign.QueryMapEncoder;
 import feign.Request;
 import feign.RequestInterceptor;
 import feign.RequestLine;
-import feign.RequestTemplate;
 import feign.Retryer;
 import feign.auth.BasicAuthRequestInterceptor;
 import feign.codec.Decoder;
@@ -34,8 +33,7 @@ import feign.hystrix.HystrixFeign;
 import feign.optionals.OptionalDecoder;
 import feign.querymap.BeanQueryMapEncoder;
 import feign.slf4j.Slf4jLogger;
-import org.junit.Test;
-import org.junit.runner.RunWith;
+import org.junit.jupiter.api.Test;
 
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.autoconfigure.context.PropertyPlaceholderAutoConfiguration;
@@ -47,7 +45,6 @@ import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.context.annotation.Import;
 import org.springframework.test.annotation.DirtiesContext;
-import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
 import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RequestMethod;
 
@@ -56,10 +53,9 @@ import static org.assertj.core.api.Assertions.assertThat;
 /**
  * @author Spencer Gibb
  */
-@RunWith(SpringJUnit4ClassRunner.class)
 @SpringBootTest(classes = FeignClientOverrideDefaultsTests.TestConfiguration.class)
 @DirtiesContext
-public class FeignClientOverrideDefaultsTests {
+class FeignClientOverrideDefaultsTests {
 
 	@Autowired
 	private FeignContext context;
@@ -71,92 +67,89 @@ public class FeignClientOverrideDefaultsTests {
 	private BarClient bar;
 
 	@Test
-	public void clientsAvailable() {
-		assertThat(this.foo).isNotNull();
-		assertThat(this.bar).isNotNull();
+	void clientsAvailable() {
+		assertThat(foo).isNotNull();
+		assertThat(bar).isNotNull();
 	}
 
 	@Test
-	public void overrideDecoder() {
-		Decoder.Default.class.cast(this.context.getInstance("foo", Decoder.class));
-		OptionalDecoder.class.cast(this.context.getInstance("bar", Decoder.class));
+	void overrideDecoder() {
+		Decoder.Default.class.cast(context.getInstance("foo", Decoder.class));
+		OptionalDecoder.class.cast(context.getInstance("bar", Decoder.class));
 	}
 
 	@Test
-	public void overrideEncoder() {
-		Encoder.Default.class.cast(this.context.getInstance("foo", Encoder.class));
-		PageableSpringEncoder.class.cast(this.context.getInstance("bar", Encoder.class));
+	void overrideEncoder() {
+		Encoder.Default.class.cast(context.getInstance("foo", Encoder.class));
+		PageableSpringEncoder.class.cast(context.getInstance("bar", Encoder.class));
 	}
 
 	@Test
-	public void overrideLogger() {
-		Logger.JavaLogger.class.cast(this.context.getInstance("foo", Logger.class));
-		Slf4jLogger.class.cast(this.context.getInstance("bar", Logger.class));
+	void overrideLogger() {
+		Logger.JavaLogger.class.cast(context.getInstance("foo", Logger.class));
+		Slf4jLogger.class.cast(context.getInstance("bar", Logger.class));
 	}
 
 	@Test
-	public void overrideContract() {
-		Contract.Default.class.cast(this.context.getInstance("foo", Contract.class));
-		SpringMvcContract.class.cast(this.context.getInstance("bar", Contract.class));
+	void overrideContract() {
+		Contract.Default.class.cast(context.getInstance("foo", Contract.class));
+		SpringMvcContract.class.cast(context.getInstance("bar", Contract.class));
 	}
 
 	@Test
-	public void overrideLoggerLevel() {
-		assertThat(this.context.getInstance("foo", Logger.Level.class)).isNull();
-		assertThat(this.context.getInstance("bar", Logger.Level.class))
+	void overrideLoggerLevel() {
+		assertThat(context.getInstance("foo", Logger.Level.class)).isNull();
+		assertThat(context.getInstance("bar", Logger.Level.class))
 				.isEqualTo(Logger.Level.HEADERS);
 	}
 
 	@Test
-	public void overrideRetryer() {
-		assertThat(this.context.getInstance("foo", Retryer.class))
+	void overrideRetryer() {
+		assertThat(context.getInstance("foo", Retryer.class))
 				.isEqualTo(Retryer.NEVER_RETRY);
-		Retryer.Default.class.cast(this.context.getInstance("bar", Retryer.class));
+		Retryer.Default.class.cast(context.getInstance("bar", Retryer.class));
 	}
 
 	@Test
-	public void overrideErrorDecoder() {
-		assertThat(this.context.getInstance("foo", ErrorDecoder.class)).isNull();
-		ErrorDecoder.Default.class
-				.cast(this.context.getInstance("bar", ErrorDecoder.class));
+	void overrideErrorDecoder() {
+		assertThat(context.getInstance("foo", ErrorDecoder.class)).isNull();
+		ErrorDecoder.Default.class.cast(context.getInstance("bar", ErrorDecoder.class));
 	}
 
 	@Test
-	public void overrideBuilder() {
-		HystrixFeign.Builder.class
-				.cast(this.context.getInstance("foo", Feign.Builder.class));
-		Feign.Builder.class.cast(this.context.getInstance("bar", Feign.Builder.class));
+	void overrideBuilder() {
+		HystrixFeign.Builder.class.cast(context.getInstance("foo", Feign.Builder.class));
+		Feign.Builder.class.cast(context.getInstance("bar", Feign.Builder.class));
 	}
 
 	@Test
-	public void overrideRequestOptions() {
-		assertThat(this.context.getInstance("foo", Request.Options.class)).isNull();
-		Request.Options options = this.context.getInstance("bar", Request.Options.class);
+	void overrideRequestOptions() {
+		assertThat(context.getInstance("foo", Request.Options.class)).isNull();
+		Request.Options options = context.getInstance("bar", Request.Options.class);
 		assertThat(options.connectTimeoutMillis()).isEqualTo(1);
 		assertThat(options.readTimeoutMillis()).isEqualTo(1);
 	}
 
 	@Test
-	public void overrideQueryMapEncoder() {
+	void overrideQueryMapEncoder() {
 		QueryMapEncoder.Default.class
-				.cast(this.context.getInstance("foo", QueryMapEncoder.class));
-		BeanQueryMapEncoder.class
-				.cast(this.context.getInstance("bar", QueryMapEncoder.class));
+				.cast(context.getInstance("foo", QueryMapEncoder.class));
+		BeanQueryMapEncoder.class.cast(context.getInstance("bar", QueryMapEncoder.class));
 	}
 
 	@Test
-	public void addRequestInterceptor() {
-		assertThat(this.context.getInstances("foo", RequestInterceptor.class).size())
+	void addRequestInterceptor() {
+		assertThat(context.getInstances("foo", RequestInterceptor.class).size())
 				.isEqualTo(1);
-		assertThat(this.context.getInstances("bar", RequestInterceptor.class).size())
+		assertThat(context.getInstances("bar", RequestInterceptor.class).size())
 				.isEqualTo(2);
 	}
 
 	@Test
-	public void exceptionPropagationPolicy() {
-		assertThat(this.context.getInstances("foo", ExceptionPropagationPolicy.class))
+	void exceptionPropagationPolicy() {
+		assertThat(context.getInstances("foo", ExceptionPropagationPolicy.class))
 				.isEmpty();
-		assertThat(this.context.getInstances("bar", ExceptionPropagationPolicy.class))
+		assertThat(context.getInstances("bar", ExceptionPropagationPolicy.class))
 				.containsValues(ExceptionPropagationPolicy.UNWRAP);
 	}
 
@@ -186,10 +179,7 @@ public class FeignClientOverrideDefaultsTests {
 
 		@Bean
 		RequestInterceptor defaultRequestInterceptor() {
-			return new RequestInterceptor() {
-				@Override
-				public void apply(RequestTemplate template) {
-				}
+			return template -> {
 			};
 		}