diff --git a/build.gradle b/build.gradle
index 47ea4c201..547175059 100644
--- a/build.gradle
+++ b/build.gradle
@@ -97,7 +97,7 @@ dependencies {
     // Slack
     implementation 'com.slack.api:slack-api-model:1.40.2'
     implementation 'com.slack.api:slack-api-client:1.40.2'
-    implementation 'com.slack.api:slack-app-backend:1.39.0'
+    implementation 'com.slack.api:slack-app-backend:1.40.3'
 
     // XSS Filter
     implementation 'com.navercorp.lucy:lucy-xss-servlet:2.0.1' // Lucy XSS Servlet Filter