diff --git a/spring-messaging/spring-messaging.gradle b/spring-messaging/spring-messaging.gradle
index cb98a9bab78..b6ceb7cedf3 100644
--- a/spring-messaging/spring-messaging.gradle
+++ b/spring-messaging/spring-messaging.gradle
@@ -7,7 +7,7 @@ dependencyManagement {
 	}
 }
 
-def rsocketVersion = "0.12.2-RC2"
+def rsocketVersion = "0.12.2-RC3-SNAPSHOT"
 
 dependencies {
 	compile(project(":spring-beans"))
diff --git a/spring-messaging/src/main/java/org/springframework/messaging/rsocket/MessageHandlerAcceptor.java b/spring-messaging/src/main/java/org/springframework/messaging/rsocket/MessageHandlerAcceptor.java
index 3a8c05fc5d8..97e3ce0f1e7 100644
--- a/spring-messaging/src/main/java/org/springframework/messaging/rsocket/MessageHandlerAcceptor.java
+++ b/spring-messaging/src/main/java/org/springframework/messaging/rsocket/MessageHandlerAcceptor.java
@@ -16,6 +16,7 @@
 
 package org.springframework.messaging.rsocket;
 
+import java.util.function.BiFunction;
 import java.util.function.Function;
 
 import io.rsocket.ConnectionSetupPayload;
@@ -26,6 +27,8 @@ import reactor.core.publisher.Mono;
 import org.springframework.lang.Nullable;
 import org.springframework.messaging.Message;
 import org.springframework.util.MimeType;
+import org.springframework.util.MimeTypeUtils;
+import org.springframework.util.StringUtils;
 
 /**
  * Extension of {@link RSocketMessageHandler} that can be plugged directly into
@@ -38,7 +41,7 @@ import org.springframework.util.MimeType;
  * @since 5.2
  */
 public final class MessageHandlerAcceptor extends RSocketMessageHandler
-		implements SocketAcceptor, Function<RSocket, RSocket> {
+		implements SocketAcceptor, BiFunction<ConnectionSetupPayload, RSocket, RSocket> {
 
 	@Nullable
 	private MimeType defaultDataMimeType;
@@ -58,7 +61,7 @@ public final class MessageHandlerAcceptor extends RSocketMessageHandler
 
 	@Override
 	public Mono<RSocket> accept(ConnectionSetupPayload setupPayload, RSocket sendingRSocket) {
-		MessagingRSocket rsocket = createRSocket(sendingRSocket);
+		MessagingRSocket rsocket = createRSocket(setupPayload, sendingRSocket);
 
 		// Allow handling of the ConnectionSetupPayload via @MessageMapping methods.
 		// However, if the handling is to make requests to the client, it's expected
@@ -67,15 +70,18 @@ public final class MessageHandlerAcceptor extends RSocketMessageHandler
 	}
 
 	@Override
-	public RSocket apply(RSocket sendingRSocket) {
-		return createRSocket(sendingRSocket);
+	public RSocket apply(ConnectionSetupPayload setupPayload, RSocket sendingRSocket) {
+		return createRSocket(setupPayload, sendingRSocket);
 	}
 
-	private MessagingRSocket createRSocket(RSocket rsocket) {
+	private MessagingRSocket createRSocket(ConnectionSetupPayload setupPayload, RSocket rsocket) {
+		MimeType dataMimeType = StringUtils.hasText(setupPayload.dataMimeType()) ?
+				MimeTypeUtils.parseMimeType(setupPayload.dataMimeType()) :
+				this.defaultDataMimeType;
 		return new MessagingRSocket(this::handleMessage,
 				route -> getRouteMatcher().parseRoute(route),
-				RSocketRequester.wrap(rsocket, this.defaultDataMimeType, getRSocketStrategies()),
-				this.defaultDataMimeType,
+				RSocketRequester.wrap(rsocket, dataMimeType, getRSocketStrategies()),
+				dataMimeType,
 				getRSocketStrategies().dataBufferFactory());
 	}
 
diff --git a/spring-messaging/src/main/java/org/springframework/messaging/rsocket/MessagingRSocket.java b/spring-messaging/src/main/java/org/springframework/messaging/rsocket/MessagingRSocket.java
index 9a4a92bfd2f..ba27d6c6ea8 100644
--- a/spring-messaging/src/main/java/org/springframework/messaging/rsocket/MessagingRSocket.java
+++ b/spring-messaging/src/main/java/org/springframework/messaging/rsocket/MessagingRSocket.java
@@ -41,9 +41,7 @@ import org.springframework.messaging.support.MessageBuilder;
 import org.springframework.messaging.support.MessageHeaderAccessor;
 import org.springframework.util.Assert;
 import org.springframework.util.MimeType;
-import org.springframework.util.MimeTypeUtils;
 import org.springframework.util.RouteMatcher;
-import org.springframework.util.StringUtils;
 
 /**
  * Implementation of {@link RSocket} that wraps incoming requests with a
@@ -70,6 +68,7 @@ class MessagingRSocket extends AbstractRSocket {
 	MessagingRSocket(Function<Message<?>, Mono<Void>> handler,
 			Function<String, RouteMatcher.Route> routeParser, RSocketRequester requester,
 			@Nullable MimeType defaultDataMimeType, DataBufferFactory bufferFactory) {
+
 		this.routeParser = routeParser;
 
 		Assert.notNull(handler, "'handler' is required");
@@ -89,9 +88,6 @@ class MessagingRSocket extends AbstractRSocket {
 	 * @return completion handle for success or error
 	 */
 	public Mono<Void> handleConnectionSetupPayload(ConnectionSetupPayload payload) {
-		if (StringUtils.hasText(payload.dataMimeType())) {
-			this.dataMimeType = MimeTypeUtils.parseMimeType(payload.dataMimeType());
-		}
 		// frameDecoder does not apply to connectionSetupPayload
 		// so retain here since handle expects it..
 		payload.retain();