diff --git a/lock.sbt b/lock.sbt
index b26a4d54c..abb2f9b3b 100644
--- a/lock.sbt
+++ b/lock.sbt
@@ -112,7 +112,7 @@ Compile / dependencyOverrides ++= {
       "javax.cache" % "cache-api" % "1.1.1",
       "javax.inject" % "javax.inject" % "1",
       "joda-time" % "joda-time" % "2.10.10",
-      "net.logstash.logback" % "logstash-logback-encoder" % "8.1",
+      "net.logstash.logback" % "logstash-logback-encoder" % "9.0",
       "net.sf.jopt-simple" % "jopt-simple" % "5.0.2",
       "nl.grons" % "metrics4-scala_2.13" % "4.3.5",
       "org.apache.commons" % "commons-email" % "1.6.0",
diff --git a/project/Dependencies.scala b/project/Dependencies.scala
index 3b4cabadd..e13f86a5b 100644
--- a/project/Dependencies.scala
+++ b/project/Dependencies.scala
@@ -145,7 +145,7 @@ object Dependencies {
 
     // See: https://github.com/logfellow/logstash-logback-encoder/releases
     // and: https://mvnrepository.com/artifact/net.logstash.logback/logstash-logback-encoder
-    val logstashLogbackEncoder = "net.logstash.logback" % "logstash-logback-encoder" % "8.1"
+    val logstashLogbackEncoder = "net.logstash.logback" % "logstash-logback-encoder" % "9.0"
     //"org.kurochan" %% "logback-stackdriver-logging" % "0.0.1",
 
     // The ElasticSearch client uses log4j-api:2.17.1 (gets evicted by 2.17.2).