diff --git a/build.gradle b/build.gradle
index 1e5a99b212..80f5e382ca 100644
--- a/build.gradle
+++ b/build.gradle
@@ -53,7 +53,7 @@ configure(allprojects) { project ->
 	ext.kotlinVersion        = "1.1.60"
 	ext.log4jVersion         = "2.9.1"
 	ext.nettyVersion         = "4.1.17.Final"
-	ext.reactorVersion       = "Bismuth-SR3"
+	ext.reactorVersion       = "Bismuth-SR4"
 	ext.rxjavaVersion        = "1.3.3"
 	ext.rxjavaAdapterVersion = "1.2.1"
 	ext.rxjava2Version       = "2.1.6"