diff --git a/cache/pom.xml b/cache/pom.xml
index 6d1cfc6cb8..28935faeb1 100644
--- a/cache/pom.xml
+++ b/cache/pom.xml
@@ -63,6 +63,7 @@
 			<groupId>org.slf4j</groupId>
 			<artifactId>slf4j-simple</artifactId>
 			<version>1.7.12</version>
+			<optional>true</optional>
 		</dependency>
 		<dependency>
 			<groupId>org.apache.commons</groupId>