diff --git a/build.gradle b/build.gradle
index 8b5b34ec6591..1ffabc3155b4 100644
--- a/build.gradle
+++ b/build.gradle
@@ -53,7 +53,7 @@ configure(allprojects) { project ->
 	ext.kotlinVersion        = "1.2.31"
 	ext.log4jVersion         = "2.11.0"
 	ext.nettyVersion         = "4.1.23.Final"
-	ext.reactorVersion       = "Bismuth-SR8"
+	ext.reactorVersion       = "Californium-BUILD-SNAPSHOT"
 	ext.rxjavaVersion        = "1.3.8"
 	ext.rxjavaAdapterVersion = "1.2.1"
 	ext.rxjava2Version       = "2.1.12"
@@ -139,6 +139,7 @@ configure(allprojects) { project ->
 
 	repositories {
 		maven { url "https://repo.spring.io/libs-release" }
+		maven { url "https://repo.spring.io/snapshot" }  // for Reactor
 	}
 
 	dependencies {