diff --git a/build.gradle b/build.gradle
index 8f3cee000..d8919e8ea 100644
--- a/build.gradle
+++ b/build.gradle
@@ -29,7 +29,7 @@ subprojects {
     apply plugin: 'io.spring.dependency-management'
     apply plugin: 'com.github.sherter.google-java-format'
 
-    ext['reactor-bom.version'] = 'Californium-SR3'
+    ext['reactor-bom.version'] = 'Californium-SR5'
     ext['logback.version'] = '1.2.3'
     ext['findbugs.version'] = '3.0.2'
     ext['netty.version'] = '4.1.31.Final'
diff --git a/rsocket-core/src/main/java/io/rsocket/internal/SwitchTransformFlux.java b/rsocket-core/src/main/java/io/rsocket/internal/SwitchTransformFlux.java
index b8ec5b863..0d2e5988e 100644
--- a/rsocket-core/src/main/java/io/rsocket/internal/SwitchTransformFlux.java
+++ b/rsocket-core/src/main/java/io/rsocket/internal/SwitchTransformFlux.java
@@ -30,6 +30,8 @@
 import reactor.util.annotation.Nullable;
 import reactor.util.context.Context;
 
+/** @deprecated in favour of {@link Flux#switchOnFirst(BiFunction)} */
+@Deprecated
 public final class SwitchTransformFlux<T, R> extends Flux<R> {
 
   final Publisher<? extends T> source;