diff --git a/build.gradle b/build.gradle
index 9fad4fc..a80e53c 100644
--- a/build.gradle
+++ b/build.gradle
@@ -44,7 +44,7 @@ if (project.hasProperty('platformVersion')) {
 
 ext {
 	servletApiVersion = '3.1.0'
-	slf4jVersion = '1.7.18'
+	slf4jVersion = '1.7.21'
 	springCloudAwsVersion = '1.1.0.RC1'
 	springIntegrationVersion = '4.2.5.RELEASE'