diff --git a/build.sbt b/build.sbt
index 13a08e63..64afde8d 100644
--- a/build.sbt
+++ b/build.sbt
@@ -8,7 +8,7 @@ Global / excludeLintKeys += webpackDevServerPort // TODO:
 val versions = new {
   val outwatch = "1.0.0-RC17"
   val colibri  = "0.7.8"
-  val funStack = "0.8.9"
+  val funStack = "0.9.21"
   val tapir    = "1.9.4"
   val pprint   = "0.8.1"
 }