diff --git a/build.sbt b/build.sbt
index f86c2a1..e02e5d0 100644
--- a/build.sbt
+++ b/build.sbt
@@ -18,7 +18,7 @@ testFrameworks += new TestFramework("zio.test.sbt.ZTestFramework")
 
 fork in Test := true
 
-val zioVersion = "2.1.19"
+val zioVersion = "2.1.21"
 
 libraryDependencies ++= {
   Seq(