diff --git a/build.gradle b/build.gradle
index 279c9e4..9901e88 100644
--- a/build.gradle
+++ b/build.gradle
@@ -17,9 +17,9 @@ configurations {
 }
 
 dependencies {
-	compile 'org.slf4j:slf4j-api:1.7.12'
+	compile 'org.slf4j:slf4j-api:1.7.21'
 	testCompile 'junit:junit:4.12'
-	testRuntime 'org.slf4j:slf4j-simple:1.7.12'
+	testRuntime 'org.slf4j:slf4j-simple:1.7.21'
 }
 
 tasks.javadoc.options.use=true