diff --git a/spring-test/src/main/java/org/springframework/test/http/MediaTypeAssert.java b/spring-test/src/main/java/org/springframework/test/http/MediaTypeAssert.java
index 6f002c8f6d..5c6077cce6 100644
--- a/spring-test/src/main/java/org/springframework/test/http/MediaTypeAssert.java
+++ b/spring-test/src/main/java/org/springframework/test/http/MediaTypeAssert.java
@@ -49,10 +49,21 @@ public class MediaTypeAssert extends AbstractObjectAssert<MediaTypeAssert, Media
 	/**
 	 * Verify that the actual media type is equal to the given string
 	 * representation.
-	 * @param expected the expected media type
+	 * @param mediaType the expected media type, as a String to be parsed
+	 * into a MediaType
+*/
+	public MediaTypeAssert isEqualTo(String mediaType) {
+		return isEqualTo(parseMediaType(mediaType));
+	}
+
+	/**
+	 * Verify that the actual media type is not equal to the given string
+	 * representation.
+	 * @param mediaType the given media type, as a String to be parsed
+	 * into a MediaType
 	 */
-	public MediaTypeAssert isEqualTo(String expected) {
-		return isEqualTo(parseMediaType(expected));
+	public MediaTypeAssert isNotEqualTo(String mediaType) {
+		return isNotEqualTo(parseMediaType(mediaType));
 	}
 
 	/**
@@ -84,7 +95,8 @@ public class MediaTypeAssert extends AbstractObjectAssert<MediaTypeAssert, Media
 	 * // Check that actual is compatible with "text/plain"
 	 * assertThat(mediaType).isCompatibleWith("text/plain");
 	 * </code></pre>
-	 * @param mediaType the media type with which to compare
+	 * @param mediaType the media type with which to compare, as a String
+	 * to be parsed into a MediaType
 	 */
 	public MediaTypeAssert isCompatibleWith(String mediaType) {
 		return isCompatibleWith(parseMediaType(mediaType));
diff --git a/spring-test/src/test/java/org/springframework/test/http/MediaTypeAssertTests.java b/spring-test/src/test/java/org/springframework/test/http/MediaTypeAssertTests.java
index 232d25400f..c8b1d71ee7 100644
--- a/spring-test/src/test/java/org/springframework/test/http/MediaTypeAssertTests.java
+++ b/spring-test/src/test/java/org/springframework/test/http/MediaTypeAssertTests.java
@@ -43,19 +43,35 @@ class MediaTypeAssertTests {
 	}
 
 	@Test
-	void isEqualWhenSameShouldPass() {
+	void isEqualWhenActualIsNullStringShouldFail() {
+		assertThatExceptionOfType(AssertionError.class)
+				.isThrownBy(() -> assertThat(null).isEqualTo("text/html"))
+				.withMessageContaining("Media type");
+	}
+
+	@Test
+	void isEqualWhenSameStringShouldPass() {
 		assertThat(mediaType("application/json")).isEqualTo("application/json");
 	}
 
 	@Test
-	void isEqualWhenDifferentShouldFail() {
+	void isEqualWhenDifferentStringShouldFail() {
 		assertThatExceptionOfType(AssertionError.class)
 				.isThrownBy(() -> assertThat(mediaType("application/json")).isEqualTo("text/html"))
 				.withMessageContaining("Media type");
 	}
 
 	@Test
-	void isEqualWhenActualIsNullShouldFail() {
+	void isEqualInvalidStringShouldFail() {
+		assertThatExceptionOfType(AssertionError.class)
+				.isThrownBy(() -> assertThat(mediaType("application/json")).isEqualTo("example of a bad value"))
+				.withMessageContaining("[Media type]")
+				.withMessageEndingWith("To be a valid media type but got:\n" +
+						"  \"Invalid mime type \"example of a bad value\": does not contain '/'\"\n");
+	}
+
+	@Test
+	void isEqualWhenActualIsNullTypeShouldFail() {
 		assertThatExceptionOfType(AssertionError.class)
 				.isThrownBy(() -> assertThat(null).isEqualTo(MediaType.APPLICATION_JSON))
 				.withMessageContaining("Media type");
@@ -73,6 +89,49 @@ class MediaTypeAssertTests {
 				.withMessageContaining("Media type");
 	}
 
+	@Test
+	void isNotEqualWhenActualIsNullStringShouldPass() {
+		assertThat(null).isNotEqualTo("application/json");
+	}
+
+	@Test
+	void isNotEqualWhenDifferentStringShouldPass() {
+		assertThat(mediaType("application/json")).isNotEqualTo("text/html");
+	}
+
+	@Test
+	void isNotEqualWhenSameStringShouldFail() {
+		assertThatExceptionOfType(AssertionError.class)
+				.isThrownBy(() -> assertThat(mediaType("application/json")).isNotEqualTo("application/json"))
+				.withMessageContaining("Media type");
+	}
+
+	@Test
+	void isNotEqualInvalidStringShouldFail() {
+		assertThatExceptionOfType(AssertionError.class)
+				.isThrownBy(() -> assertThat(mediaType("application/json")).isNotEqualTo("example of a bad value"))
+				.withMessageContaining("[Media type]")
+				.withMessageEndingWith("To be a valid media type but got:\n" +
+						"  \"Invalid mime type \"example of a bad value\": does not contain '/'\"\n");
+	}
+
+	@Test
+	void isNotEqualWhenActualIsNullTypeShouldPass() {
+		assertThat(null).isNotEqualTo(MediaType.APPLICATION_JSON);
+	}
+
+	@Test
+	void isNotEqualWhenDifferentTypeShouldPass() {
+		assertThat(mediaType("application/json")).isNotEqualTo(MediaType.TEXT_HTML);
+	}
+
+	@Test
+	void isNotEqualWhenSameTypeShouldFail() {
+		assertThatExceptionOfType(AssertionError.class)
+				.isThrownBy(() -> assertThat(mediaType("application/json")).isNotEqualTo(MediaType.APPLICATION_JSON))
+				.withMessageContaining("Media type");
+	}
+
 	@Test
 	void isCompatibleWhenSameShouldPass() {
 		assertThat(mediaType("application/json")).isCompatibleWith("application/json");