diff --git a/pom.xml b/pom.xml
index b65c4b7d6..d1fd25e09 100644
--- a/pom.xml
+++ b/pom.xml
@@ -349,7 +349,7 @@
         <dependency>
             <groupId>org.slf4j</groupId>
             <artifactId>slf4j-simple</artifactId>
-            <version>1.7.20</version>
+            <version>1.7.21</version>
             <scope>compile</scope>
             <optional>true</optional>
         </dependency>