diff --git a/config/src/test/java/org/springframework/security/config/annotation/method/configuration/EnableReactiveMethodSecurityTests.java b/config/src/test/java/org/springframework/security/config/annotation/method/configuration/EnableReactiveMethodSecurityTests.java
index 44e6e6a0d3..4a905ebe88 100644
--- a/config/src/test/java/org/springframework/security/config/annotation/method/configuration/EnableReactiveMethodSecurityTests.java
+++ b/config/src/test/java/org/springframework/security/config/annotation/method/configuration/EnableReactiveMethodSecurityTests.java
@@ -16,7 +16,6 @@
 
 package org.springframework.security.config.annotation.method.configuration;
 
-import org.assertj.core.api.AssertionsForClassTypes;
 import org.junit.After;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -35,6 +34,7 @@ import org.springframework.security.core.context.ReactiveSecurityContextHolder;
 import org.springframework.test.context.ContextConfiguration;
 import org.springframework.test.context.junit4.SpringRunner;
 
+import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
 import static org.mockito.BDDMockito.given;
 import static org.mockito.Mockito.mock;
@@ -200,8 +200,7 @@ public class EnableReactiveMethodSecurityTests {
 		given(this.delegate.fluxPreAuthorizeHasRoleFindById(1L)).willReturn(Flux.just("result"));
 		Flux<String> findById = this.messageService.fluxPreAuthorizeHasRoleFindById(1L)
 				.subscriberContext(this.withAdmin);
-		StepVerifier.create(findById).consumeNextWith((s) -> AssertionsForClassTypes.assertThat(s).isEqualTo("result"))
-				.verifyComplete();
+		StepVerifier.create(findById).consumeNextWith((s) -> assertThat(s).isEqualTo("result")).verifyComplete();
 	}
 
 	@Test
@@ -305,8 +304,7 @@ public class EnableReactiveMethodSecurityTests {
 		given(this.delegate.publisherPreAuthorizeHasRoleFindById(1L)).willReturn(publisherJust("result"));
 		Publisher<String> findById = Flux.from(this.messageService.publisherPreAuthorizeHasRoleFindById(1L))
 				.subscriberContext(this.withAdmin);
-		StepVerifier.create(findById).consumeNextWith((s) -> AssertionsForClassTypes.assertThat(s).isEqualTo("result"))
-				.verifyComplete();
+		StepVerifier.create(findById).consumeNextWith((s) -> assertThat(s).isEqualTo("result")).verifyComplete();
 	}
 
 	@Test
diff --git a/core/src/test/java/org/springframework/security/converter/RsaKeyConvertersTests.java b/core/src/test/java/org/springframework/security/converter/RsaKeyConvertersTests.java
index 62017aa038..17019a626f 100644
--- a/core/src/test/java/org/springframework/security/converter/RsaKeyConvertersTests.java
+++ b/core/src/test/java/org/springframework/security/converter/RsaKeyConvertersTests.java
@@ -24,11 +24,12 @@ import java.security.interfaces.RSAPrivateKey;
 import java.security.interfaces.RSAPublicKey;
 
 import org.assertj.core.api.Assertions;
-import org.assertj.core.api.AssertionsForClassTypes;
 import org.junit.Test;
 
 import org.springframework.core.convert.converter.Converter;
 
+import static org.assertj.core.api.Assertions.assertThatCode;
+
 /**
  * Tests for {@link RsaKeyConverters}
  */
@@ -98,7 +99,7 @@ public class RsaKeyConvertersTests {
 
 	@Test
 	public void pkcs8WhenConvertingPkcs1PrivateKeyThenIllegalArgumentException() {
-		AssertionsForClassTypes.assertThatCode(() -> this.pkcs8.convert(toInputStream(PKCS1_PRIVATE_KEY)))
+		assertThatCode(() -> this.pkcs8.convert(toInputStream(PKCS1_PRIVATE_KEY)))
 				.isInstanceOf(IllegalArgumentException.class);
 	}
 
@@ -110,7 +111,7 @@ public class RsaKeyConvertersTests {
 
 	@Test
 	public void x509WhenConvertingDerEncodedX509PublicKeyThenIllegalArgumentException() {
-		AssertionsForClassTypes.assertThatCode(() -> this.x509.convert(toInputStream(MALFORMED_X509_KEY)))
+		assertThatCode(() -> this.x509.convert(toInputStream(MALFORMED_X509_KEY)))
 				.isInstanceOf(IllegalArgumentException.class);
 	}
 
diff --git a/oauth2/oauth2-jose/src/test/java/org/springframework/security/oauth2/jwt/NimbusReactiveJwtDecoderTests.java b/oauth2/oauth2-jose/src/test/java/org/springframework/security/oauth2/jwt/NimbusReactiveJwtDecoderTests.java
index 237e3ba2c4..164877f904 100644
--- a/oauth2/oauth2-jose/src/test/java/org/springframework/security/oauth2/jwt/NimbusReactiveJwtDecoderTests.java
+++ b/oauth2/oauth2-jose/src/test/java/org/springframework/security/oauth2/jwt/NimbusReactiveJwtDecoderTests.java
@@ -47,7 +47,6 @@ import com.nimbusds.jwt.JWTClaimsSet;
 import com.nimbusds.jwt.SignedJWT;
 import okhttp3.mockwebserver.MockResponse;
 import okhttp3.mockwebserver.MockWebServer;
-import org.assertj.core.api.AssertionsForClassTypes;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.BeforeClass;
@@ -345,7 +344,7 @@ public class NimbusReactiveJwtDecoderTests {
 				.jwtProcessorCustomizer(
 						(p) -> p.setJWSTypeVerifier(new DefaultJOSEObjectTypeVerifier<>(new JOSEObjectType("JWS"))))
 				.build();
-		AssertionsForClassTypes.assertThatCode(() -> decoder.decode(this.rsa256).block())
+		assertThatCode(() -> decoder.decode(this.rsa256).block())
 				.isInstanceOf(BadJwtException.class)
 				.hasRootCauseMessage("Required JOSE header \"typ\" (type) parameter is missing");
 	}