diff --git a/spring-core/src/main/java/org/springframework/util/MimeType.java b/spring-core/src/main/java/org/springframework/util/MimeType.java
index 2512ecd69d..a2ff8055ca 100644
--- a/spring-core/src/main/java/org/springframework/util/MimeType.java
+++ b/spring-core/src/main/java/org/springframework/util/MimeType.java
@@ -165,8 +165,8 @@ public class MimeType implements Comparable<MimeType>, Serializable {
 	 * @throws IllegalArgumentException if any of the parameters contains illegal characters
 	 */
 	public MimeType(String type, String subtype, Map<String, String> parameters) {
-		Assert.hasLength(type, "type must not be empty");
-		Assert.hasLength(subtype, "subtype must not be empty");
+		Assert.hasLength(type, "'type' must not be empty");
+		Assert.hasLength(subtype, "'subtype' must not be empty");
 		checkToken(type);
 		checkToken(subtype);
 		this.type = type.toLowerCase(Locale.ENGLISH);
@@ -202,8 +202,8 @@ public class MimeType implements Comparable<MimeType>, Serializable {
 	}
 
 	protected void checkParameters(String attribute, String value) {
-		Assert.hasLength(attribute, "parameter attribute must not be empty");
-		Assert.hasLength(value, "parameter value must not be empty");
+		Assert.hasLength(attribute, "'attribute' must not be empty");
+		Assert.hasLength(value, "'value' must not be empty");
 		checkToken(attribute);
 		if (PARAM_CHARSET.equals(attribute)) {
 			value = unquote(value);
@@ -277,8 +277,8 @@ public class MimeType implements Comparable<MimeType>, Serializable {
 	 * @since 4.3
 	 */
 	public Charset getCharset() {
-		String charSet = getParameter(PARAM_CHARSET);
-		return (charSet != null ? Charset.forName(unquote(charSet)) : null);
+		String charset = getParameter(PARAM_CHARSET);
+		return (charset != null ? Charset.forName(unquote(charset)) : null);
 	}
 
 	/**
diff --git a/spring-core/src/main/java/org/springframework/util/MimeTypeUtils.java b/spring-core/src/main/java/org/springframework/util/MimeTypeUtils.java
index 968942cd08..581334e7bc 100644
--- a/spring-core/src/main/java/org/springframework/util/MimeTypeUtils.java
+++ b/spring-core/src/main/java/org/springframework/util/MimeTypeUtils.java
@@ -47,6 +47,11 @@ public abstract class MimeTypeUtils {
 
 	private static final Random RND = new Random();
 
+	/**
+	 * Comparator used by {@link #sortBySpecificity(List)}.
+	 */
+	public static final Comparator<MimeType> SPECIFICITY_COMPARATOR = new SpecificityComparator<>();
+
 	/**
 	 * Public constant mime type that includes all media ranges (i.e. "&#42;/&#42;").
 	 */
@@ -216,12 +221,13 @@ public abstract class MimeTypeUtils {
 		if (!StringUtils.hasLength(mimeType)) {
 			throw new InvalidMimeTypeException(mimeType, "'mimeType' must not be empty");
 		}
-		String[] parts = StringUtils.tokenizeToStringArray(mimeType, ";");
-		if (parts.length == 0) {
+
+		int index = mimeType.indexOf(';');
+		String fullType = (index >= 0 ? mimeType.substring(0, index) : mimeType).trim();
+		if (fullType.length() == 0) {
 			throw new InvalidMimeTypeException(mimeType, "'mimeType' must not be empty");
 		}
 
-		String fullType = parts[0].trim();
 		// java.net.HttpURLConnection returns a *; q=.2 Accept header
 		if (MimeType.WILDCARD_TYPE.equals(fullType)) {
 			fullType = "*/*";
@@ -240,18 +246,36 @@ public abstract class MimeTypeUtils {
 		}
 
 		Map<String, String> parameters = null;
-		if (parts.length > 1) {
-			parameters = new LinkedHashMap<>(parts.length - 1);
-			for (int i = 1; i < parts.length; i++) {
-				String parameter = parts[i];
+		do {
+			int nextIndex = index + 1;
+			boolean quoted = false;
+			while (nextIndex < mimeType.length()) {
+				char ch = mimeType.charAt(nextIndex);
+				if (ch == ';') {
+					if (!quoted) {
+						break;
+					}
+				}
+				else if (ch == '"') {
+					quoted = !quoted;
+				}
+				nextIndex++;
+			}
+			String parameter = mimeType.substring(index + 1, nextIndex).trim();
+			if (parameter.length() > 0) {
+				if (parameters == null) {
+					parameters = new LinkedHashMap<>(4);
+				}
 				int eqIndex = parameter.indexOf('=');
-				if (eqIndex != -1) {
+				if (eqIndex >= 0) {
 					String attribute = parameter.substring(0, eqIndex);
 					String value = parameter.substring(eqIndex + 1, parameter.length());
 					parameters.put(attribute, value);
 				}
 			}
+			index = nextIndex;
 		}
+		while (index < mimeType.length());
 
 		try {
 			return new MimeType(type, subtype, parameters);
@@ -350,11 +374,4 @@ public abstract class MimeTypeUtils {
 		return new String(generateMultipartBoundary(), StandardCharsets.US_ASCII);
 	}
 
-
-
-	/**
-	 * Comparator used by {@link #sortBySpecificity(List)}.
-	 */
-	public static final Comparator<MimeType> SPECIFICITY_COMPARATOR = new SpecificityComparator<>();
-
 }
diff --git a/spring-core/src/test/java/org/springframework/util/MimeTypeTests.java b/spring-core/src/test/java/org/springframework/util/MimeTypeTests.java
index dc797f88cd..49961078f1 100644
--- a/spring-core/src/test/java/org/springframework/util/MimeTypeTests.java
+++ b/spring-core/src/test/java/org/springframework/util/MimeTypeTests.java
@@ -87,6 +87,16 @@ public class MimeTypeTests {
 		assertEquals("Invalid charset", StandardCharsets.UTF_8, mimeType.getCharset());
 	}
 
+	@Test
+	public void parseQuotedSeparator() {
+		String s = "application/xop+xml;charset=utf-8;type=\"application/soap+xml;action=\\\"http://x.y.z\\\"\"";
+		MimeType mimeType = MimeType.valueOf(s);
+		assertEquals("Invalid type", "application", mimeType.getType());
+		assertEquals("Invalid subtype", "xop+xml", mimeType.getSubtype());
+		assertEquals("Invalid charset", StandardCharsets.UTF_8, mimeType.getCharset());
+		assertEquals("\"application/soap+xml;action=\\\"http://x.y.z\\\"\"", mimeType.getParameter("type"));
+	}
+
 	@Test
 	public void withConversionService() {
 		ConversionService conversionService = new DefaultConversionService();