diff --git a/send-notification/pom.xml b/send-notification/pom.xml
index 06ae3a6..c22864d 100644
--- a/send-notification/pom.xml
+++ b/send-notification/pom.xml
@@ -70,7 +70,7 @@
         <dependency>
             <groupId>com.google.guava</groupId>
             <artifactId>guava</artifactId>
-            <version>18.0</version>
+            <version>23.0</version>
         </dependency>
         <dependency>
             <groupId>com.dorkbox</groupId>