diff --git a/spring-web/src/main/java/org/springframework/http/converter/ResourceRegionHttpMessageConverter.java b/spring-web/src/main/java/org/springframework/http/converter/ResourceRegionHttpMessageConverter.java
index 35e98ddd08c..6a23f98e464 100644
--- a/spring-web/src/main/java/org/springframework/http/converter/ResourceRegionHttpMessageConverter.java
+++ b/spring-web/src/main/java/org/springframework/http/converter/ResourceRegionHttpMessageConverter.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 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.
@@ -29,7 +29,9 @@ import org.springframework.http.HttpHeaders;
 import org.springframework.http.HttpInputMessage;
 import org.springframework.http.HttpOutputMessage;
 import org.springframework.http.MediaType;
+import org.springframework.http.MediaTypeFactory;
 import org.springframework.util.Assert;
+import org.springframework.util.ClassUtils;
 import org.springframework.util.MimeTypeUtils;
 import org.springframework.util.StreamUtils;
 
@@ -42,6 +44,9 @@ import org.springframework.util.StreamUtils;
  */
 public class ResourceRegionHttpMessageConverter extends AbstractGenericHttpMessageConverter<Object> {
 
+	private static final boolean jafPresent = ClassUtils.isPresent(
+			"javax.activation.FileTypeMap", ResourceHttpMessageConverter.class.getClassLoader());
+
 	public ResourceRegionHttpMessageConverter() {
 		super(MediaType.ALL);
 	}
@@ -72,6 +77,23 @@ public class ResourceRegionHttpMessageConverter extends AbstractGenericHttpMessa
 		return null;
 	}
 
+	@Override
+	@SuppressWarnings("unchecked")
+	protected MediaType getDefaultContentType(Object object) {
+		if (jafPresent) {
+			if(object instanceof ResourceRegion) {
+				return MediaTypeFactory.getMediaType(((ResourceRegion) object).getResource());
+			}
+			else {
+				Collection<ResourceRegion> regions = (Collection<ResourceRegion>) object;
+				if(regions.size() > 0) {
+					return MediaTypeFactory.getMediaType(regions.iterator().next().getResource());
+				}
+			}
+		}
+		return MediaType.APPLICATION_OCTET_STREAM;
+	}
+
 	@Override
 	public boolean canWrite(Class<?> clazz, MediaType mediaType) {
 		return canWrite(clazz, null, mediaType);
diff --git a/spring-web/src/test/java/org/springframework/http/converter/ResourceRegionHttpMessageConverterTests.java b/spring-web/src/test/java/org/springframework/http/converter/ResourceRegionHttpMessageConverterTests.java
index b75d596ea45..e05595569bd 100644
--- a/spring-web/src/test/java/org/springframework/http/converter/ResourceRegionHttpMessageConverterTests.java
+++ b/spring-web/src/test/java/org/springframework/http/converter/ResourceRegionHttpMessageConverterTests.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2016 the original author or authors.
+ * Copyright 2002-2017 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.
@@ -16,13 +16,17 @@
 
 package org.springframework.http.converter;
 
+import java.io.ByteArrayInputStream;
 import java.lang.reflect.Type;
 import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 
 import org.hamcrest.Matchers;
 import org.junit.Test;
+import org.mockito.BDDMockito;
+import org.mockito.Mockito;
 
 import org.springframework.core.ParameterizedTypeReference;
 import org.springframework.core.io.ClassPathResource;
@@ -34,8 +38,10 @@ import org.springframework.http.MediaType;
 import org.springframework.http.MockHttpOutputMessage;
 import org.springframework.util.StringUtils;
 
-import static org.hamcrest.Matchers.*;
-import static org.junit.Assert.*;
+import static org.hamcrest.Matchers.is;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertThat;
+import static org.junit.Assert.assertTrue;
 
 /**
  * Test cases for {@link ResourceRegionHttpMessageConverter} class.
@@ -139,4 +145,21 @@ public class ResourceRegionHttpMessageConverterTests {
 		assertThat(ranges[15], is("resource content."));
 	}
 
+	@Test // SPR-15041
+	public void applicationOctetStreamDefaultContentType() throws Exception {
+		MockHttpOutputMessage outputMessage = new MockHttpOutputMessage();
+		ClassPathResource body = Mockito.mock(ClassPathResource.class);
+		BDDMockito.given(body.getFilename()).willReturn("spring.dat");
+		BDDMockito.given(body.contentLength()).willReturn(12L);
+		BDDMockito.given(body.getInputStream()).willReturn(new ByteArrayInputStream("Spring Framework".getBytes()));
+		HttpRange range = HttpRange.createByteRange(0, 5);
+		ResourceRegion resourceRegion = range.toResourceRegion(body);
+
+		converter.write(Collections.singletonList(resourceRegion), null, outputMessage);
+
+		assertThat(outputMessage.getHeaders().getContentType(), is(MediaType.APPLICATION_OCTET_STREAM));
+		assertThat(outputMessage.getHeaders().getFirst(HttpHeaders.CONTENT_RANGE), is("bytes 0-5/12"));
+		assertThat(outputMessage.getBodyAsString(StandardCharsets.UTF_8), is("Spring"));
+	}
+
 }
\ No newline at end of file