diff --git a/build.gradle b/build.gradle
index 608c513edb..5dff30fc67 100644
--- a/build.gradle
+++ b/build.gradle
@@ -125,7 +125,7 @@ subprojects { subproject ->
 		pahoMqttClientVersion = '1.1.1'
 		postgresVersion = '42.0.0'
 		reactorNettyVersion = '0.6.4.RELEASE'
-		reactorVersion = '3.1.0.M2'
+		reactorVersion = '3.1.0.M1'
 		romeToolsVersion = '1.7.2'
 		servletApiVersion = '3.1.0'
 		slf4jVersion = "1.7.25"