diff --git a/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/thymeleaf/ThymeleafAutoConfiguration.java b/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/thymeleaf/ThymeleafAutoConfiguration.java
index 22ebd40f93..f4398accce 100644
--- a/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/thymeleaf/ThymeleafAutoConfiguration.java
+++ b/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/thymeleaf/ThymeleafAutoConfiguration.java
@@ -19,6 +19,7 @@ package org.springframework.boot.autoconfigure.thymeleaf;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.LinkedHashMap;
+import java.util.List;
 
 import javax.annotation.PostConstruct;
 
@@ -55,6 +56,7 @@ import org.springframework.context.ApplicationContext;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.core.Ordered;
+import org.springframework.http.MediaType;
 import org.springframework.util.MimeType;
 import org.springframework.web.servlet.resource.ResourceUrlEncodingFilter;
 
@@ -252,8 +254,10 @@ public class ThymeleafAutoConfiguration {
 			ThymeleafReactiveViewResolver resolver = new ThymeleafReactiveViewResolver();
 			resolver.setTemplateEngine(templateEngine);
 			resolver.setDefaultCharset(this.properties.getEncoding());
-			resolver.setSupportedMediaTypes(
-					this.properties.getReactive().getMediaTypes());
+			final List<MediaType> mediaTypes = this.properties.getReactive().getMediaTypes();
+			if (mediaTypes != null) {
+				resolver.setSupportedMediaTypes(mediaTypes);
+			}
 			resolver.setExcludedViewNames(this.properties.getExcludedViewNames());
 			resolver.setViewNames(this.properties.getViewNames());
 			if (this.properties.getReactive().getMaxChunkSize() > 0) {
diff --git a/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/thymeleaf/ThymeleafProperties.java b/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/thymeleaf/ThymeleafProperties.java
index daa5386a72..e403f505b6 100644
--- a/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/thymeleaf/ThymeleafProperties.java
+++ b/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/thymeleaf/ThymeleafProperties.java
@@ -17,8 +17,6 @@
 package org.springframework.boot.autoconfigure.thymeleaf;
 
 import java.nio.charset.Charset;
-import java.util.ArrayList;
-import java.util.Collections;
 import java.util.List;
 
 import org.springframework.boot.context.properties.ConfigurationProperties;
@@ -227,8 +225,7 @@ public class ThymeleafProperties {
 		/**
 		 * Media types supported by the view technology.
 		 */
-		private List<MediaType> mediaTypes = new ArrayList<>(
-				Collections.singletonList(MediaType.TEXT_HTML));
+		private List<MediaType> mediaTypes;
 
 		public List<MediaType> getMediaTypes() {
 			return this.mediaTypes;
diff --git a/spring-boot-docs/src/main/asciidoc/appendix-application-properties.adoc b/spring-boot-docs/src/main/asciidoc/appendix-application-properties.adoc
index 5a62db5471..f5c55b3910 100644
--- a/spring-boot-docs/src/main/asciidoc/appendix-application-properties.adoc
+++ b/spring-boot-docs/src/main/asciidoc/appendix-application-properties.adoc
@@ -441,7 +441,7 @@ content into your application; rather pick only the properties that you need.
 	spring.thymeleaf.mode=HTML5 # Template mode to be applied to templates. See also StandardTemplateModeHandlers.
 	spring.thymeleaf.prefix=classpath:/templates/ # Prefix that gets prepended to view names when building a URL.
 	spring.thymeleaf.reactive.max-chunk-size= # Maximum size of data buffers used for writing to the response, in bytes.
-	spring.thymeleaf.reactive.media-types=text/html # Media types supported by the view technology.
+	spring.thymeleaf.reactive.media-types= # Media types supported by the view technology.
 	spring.thymeleaf.servlet.content-type=text/html # Content-Type value written to HTTP responses.
 	spring.thymeleaf.suffix=.html # Suffix that gets appended to view names when building a URL.
 	spring.thymeleaf.template-resolver-order= # Order of the template resolver in the chain.