diff --git a/spring-web/src/main/java/org/springframework/http/codec/multipart/MultipartParser.java b/spring-web/src/main/java/org/springframework/http/codec/multipart/MultipartParser.java
index d797b99f4b1..ff1344424aa 100644
--- a/spring-web/src/main/java/org/springframework/http/codec/multipart/MultipartParser.java
+++ b/spring-web/src/main/java/org/springframework/http/codec/multipart/MultipartParser.java
@@ -17,8 +17,12 @@
 package org.springframework.http.codec.multipart;
 
 import java.nio.charset.Charset;
+import java.util.ArrayDeque;
 import java.util.ArrayList;
+import java.util.Deque;
+import java.util.Iterator;
 import java.util.List;
+import java.util.concurrent.ConcurrentLinkedDeque;
 import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.concurrent.atomic.AtomicReference;
@@ -477,11 +481,14 @@ final class MultipartParser extends BaseSubscriber<DataBuffer> {
 
 		private final DataBufferUtils.Matcher boundary;
 
-		private final AtomicReference<DataBuffer> previous = new AtomicReference<>();
+		private final int boundaryLength;
+
+		private final Deque<DataBuffer> queue = new ConcurrentLinkedDeque<>();
 
 		public BodyState() {
-			this.boundary = DataBufferUtils.matcher(
-					MultipartUtils.concat(CR_LF, TWO_HYPHENS, MultipartParser.this.boundary));
+			byte[] delimiter = MultipartUtils.concat(CR_LF, TWO_HYPHENS, MultipartParser.this.boundary);
+			this.boundary = DataBufferUtils.matcher(delimiter);
+			this.boundaryLength = delimiter.length;
 		}
 
 		/**
@@ -499,31 +506,38 @@ final class MultipartParser extends BaseSubscriber<DataBuffer> {
 				if (logger.isTraceEnabled()) {
 					logger.trace("Boundary found @" + endIdx + " in " + buffer);
 				}
-				int len = endIdx - buffer.readPosition() - this.boundary.delimiter().length + 1;
+				int len = endIdx - buffer.readPosition() - this.boundaryLength + 1;
 				if (len > 0) {
-					// buffer contains complete delimiter, let's slice it and flush it
+					// whole boundary in buffer.
+					// slice off the body part, and flush
 					DataBuffer body = buffer.retainedSlice(buffer.readPosition(), len);
 					enqueue(body);
-					enqueue(null);
+					flush();
 				}
 				else if (len < 0) {
-					// buffer starts with the end of the delimiter, let's slice the previous buffer and flush it
-					DataBuffer previous = this.previous.get();
-					int prevLen = previous.readableByteCount() + len;
-					if (prevLen > 0) {
-						DataBuffer body = previous.retainedSlice(previous.readPosition(), prevLen);
-						DataBufferUtils.release(previous);
-						this.previous.set(body);
-						enqueue(null);
-					}
-					else {
-						DataBufferUtils.release(previous);
-						this.previous.set(null);
+					// boundary spans multiple buffers, and we've just found the end
+					// iterate over buffers in reverse order
+					DataBuffer prev;
+					while ((prev = this.queue.pollLast()) != null) {
+						int prevLen = prev.readableByteCount() + len;
+						if (prevLen > 0) {
+							// slice body part of previous buffer, and flush it
+							DataBuffer body = prev.retainedSlice(prev.readPosition(), prevLen);
+							DataBufferUtils.release(prev);
+							enqueue(body);
+							flush();
+							break;
+						}
+						else {
+							// previous buffer only contains boundary bytes
+							DataBufferUtils.release(prev);
+							len += prev.readableByteCount();
+						}
 					}
 				}
-				else /* if (sliceLength == 0) */ {
-					// buffer starts with complete delimiter, flush out the previous buffer
-					enqueue(null);
+				else /* if (len == 0) */ {
+					// buffer starts with complete delimiter, flush out the previous buffers
+					flush();
 				}
 
 				DataBuffer remainder = MultipartUtils.sliceFrom(buffer, endIdx);
@@ -538,13 +552,32 @@ final class MultipartParser extends BaseSubscriber<DataBuffer> {
 		}
 
 		/**
-		 * Stores the given buffer and sends out the previous buffer.
+		 * Store the given buffer. Emit buffers that cannot contain boundary bytes,
+		 * by iterating over the queue in reverse order, and summing buffer sizes.
+		 * The first buffer that passes the boundary length and subsequent buffers
+		 * are emitted (in the correct, non-reverse order).
 		 */
-		private void enqueue(@Nullable DataBuffer buf) {
-			DataBuffer previous = this.previous.getAndSet(buf);
-			if (previous != null) {
-				emitBody(previous);
+		private void enqueue(DataBuffer buf) {
+			this.queue.add(buf);
+
+			int len = 0;
+			Deque<DataBuffer> emit = new ArrayDeque<>();
+			for (Iterator<DataBuffer> iterator = this.queue.descendingIterator(); iterator.hasNext(); ) {
+				DataBuffer previous = iterator.next();
+				if (len > this.boundaryLength) {
+					// addFirst to negate iterating in reverse order
+					emit.addFirst(previous);
+					iterator.remove();
+				}
+				len += previous.readableByteCount();
 			}
+
+			emit.forEach(MultipartParser.this::emitBody);
+		}
+
+		private void flush() {
+			this.queue.forEach(MultipartParser.this::emitBody);
+			this.queue.clear();
 		}
 
 		@Override
@@ -556,10 +589,8 @@ final class MultipartParser extends BaseSubscriber<DataBuffer> {
 
 		@Override
 		public void dispose() {
-			DataBuffer previous = this.previous.getAndSet(null);
-			if (previous != null) {
-				DataBufferUtils.release(previous);
-			}
+			this.queue.forEach(DataBufferUtils::release);
+			this.queue.clear();
 		}
 
 		@Override
diff --git a/spring-webflux/src/test/java/org/springframework/web/reactive/result/method/annotation/MultipartIntegrationTests.java b/spring-webflux/src/test/java/org/springframework/web/reactive/result/method/annotation/MultipartIntegrationTests.java
index 98da50cd66f..b60587452ac 100644
--- a/spring-webflux/src/test/java/org/springframework/web/reactive/result/method/annotation/MultipartIntegrationTests.java
+++ b/spring-webflux/src/test/java/org/springframework/web/reactive/result/method/annotation/MultipartIntegrationTests.java
@@ -211,10 +211,9 @@ class MultipartIntegrationTests extends AbstractHttpHandlerIntegrationTests {
 
 	private static void verifyContents(Path tempFile, Resource resource) {
 		try {
-			byte[] tempBytes = Files.readAllBytes(tempFile);
 			// Use FileCopyUtils since the resource might reside in a JAR instead of in the file system.
 			byte[] resourceBytes = FileCopyUtils.copyToByteArray(resource.getInputStream());
-			assertThat(tempBytes).isEqualTo(resourceBytes);
+			assertThat(tempFile).hasBinaryContent(resourceBytes);
 		}
 		catch (IOException ex) {
 			throw new AssertionError(ex);