diff --git a/spring-test/src/main/java/org/springframework/test/web/reactive/server/ExchangeResult.java b/spring-test/src/main/java/org/springframework/test/web/reactive/server/ExchangeResult.java
index e4ee98e8a0..2359b13847 100644
--- a/spring-test/src/main/java/org/springframework/test/web/reactive/server/ExchangeResult.java
+++ b/spring-test/src/main/java/org/springframework/test/web/reactive/server/ExchangeResult.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -24,6 +24,8 @@ import java.util.Arrays;
 import java.util.List;
 import java.util.stream.Collectors;
 
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
 import reactor.core.publisher.Mono;
 
 import org.springframework.http.HttpHeaders;
@@ -54,6 +56,8 @@ import org.springframework.util.MultiValueMap;
  */
 public class ExchangeResult {
 
+	private static Log logger = LogFactory.getLog(ExchangeResult.class);
+
 	private static final List<MediaType> PRINTABLE_MEDIA_TYPES = Arrays.asList(
 			MediaType.APPLICATION_JSON, MediaType.APPLICATION_XML,
 			MediaType.parseMediaType("text/*"), MediaType.APPLICATION_FORM_URLENCODED);
@@ -223,7 +227,10 @@ public class ExchangeResult {
 			assertion.run();
 		}
 		catch (AssertionError ex) {
-			throw new AssertionError(ex.getMessage() + "\n" + this, ex);
+			if (logger.isErrorEnabled()) {
+				logger.error("Request details for assertion failure:\n" + this);
+			}
+			throw ex;
 		}
 	}
 
diff --git a/spring-test/src/test/java/org/springframework/test/web/reactive/server/HeaderAssertionTests.java b/spring-test/src/test/java/org/springframework/test/web/reactive/server/HeaderAssertionTests.java
index b1e6ced4b1..bc3dc33b09 100644
--- a/spring-test/src/test/java/org/springframework/test/web/reactive/server/HeaderAssertionTests.java
+++ b/spring-test/src/test/java/org/springframework/test/web/reactive/server/HeaderAssertionTests.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2021 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -100,7 +100,7 @@ class HeaderAssertionTests {
 		// Wrong pattern
 		assertThatExceptionOfType(AssertionError.class)
 				.isThrownBy(() -> assertions.valueMatches("Content-Type", ".*ISO-8859-1.*"))
-				.satisfies(ex -> assertThat(ex.getCause()).hasMessage("Response header " +
+				.satisfies(ex -> assertThat(ex).hasMessage("Response header " +
 						"'Content-Type'=[application/json;charset=UTF-8] does not match " +
 						"[.*ISO-8859-1.*]"));
 	}
@@ -117,13 +117,13 @@ class HeaderAssertionTests {
 
 		assertThatExceptionOfType(AssertionError.class)
 				.isThrownBy(() -> assertions.valuesMatch("foo", ".*", "val.*5"))
-				.satisfies(ex -> assertThat(ex.getCause()).hasMessage(
+				.satisfies(ex -> assertThat(ex).hasMessage(
 						"Response header 'foo' has fewer or more values [value1, value2, value3] " +
 								"than number of patterns to match with [.*, val.*5]"));
 
 		assertThatExceptionOfType(AssertionError.class)
 				.isThrownBy(() -> assertions.valuesMatch("foo", ".*", "val.*5", ".*"))
-				.satisfies(ex -> assertThat(ex.getCause()).hasMessage(
+				.satisfies(ex -> assertThat(ex).hasMessage(
 						"Response header 'foo'[1]='value2' does not match 'val.*5'"));
 	}
 
@@ -158,7 +158,7 @@ class HeaderAssertionTests {
 		// Header should not exist
 		assertThatExceptionOfType(AssertionError.class).isThrownBy(() ->
 				assertions.exists("Framework"))
-			.satisfies(ex -> assertThat(ex.getCause()).hasMessage("Response header 'Framework' does not exist"));
+			.satisfies(ex -> assertThat(ex).hasMessage("Response header 'Framework' does not exist"));
 	}
 
 	@Test
@@ -173,7 +173,7 @@ class HeaderAssertionTests {
 		// Existing header
 		assertThatExceptionOfType(AssertionError.class).isThrownBy(() ->
 				assertions.doesNotExist("Content-Type"))
-			.satisfies(ex -> assertThat(ex.getCause()).hasMessage("Response header " +
+			.satisfies(ex -> assertThat(ex).hasMessage("Response header " +
 					"'Content-Type' exists with value=[application/json;charset=UTF-8]"));
 	}
 
@@ -189,7 +189,6 @@ class HeaderAssertionTests {
 		// MediaTypes not compatible
 		assertThatExceptionOfType(AssertionError.class)
 			.isThrownBy(() -> assertions.contentTypeCompatibleWith(MediaType.TEXT_XML))
-			.havingCause()
 			.withMessage("Response header 'Content-Type'=[application/xml] is not compatible with [text/xml]");
 	}