diff --git a/build.sbt b/build.sbt
index 2bf1536..69f44f5 100644
--- a/build.sbt
+++ b/build.sbt
@@ -38,7 +38,7 @@ lazy val root = (project in file("."))
       ++ Seq(
         "net.logstash.logback" % "logstash-logback-encoder" % "8.0",
         // Transient dependency of Play. No newer version of Play 2.9 or Play 3.0 with this vulnerability fixed.
-        "ch.qos.logback" % "logback-classic" % "1.5.8",
+        "ch.qos.logback" % "logback-classic" % "1.5.9",
       ),
 
     buildInfoKeys ++= Seq[BuildInfoKey](