diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index db0900e..69e17cb 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -22,7 +22,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest]
-        scala: [2.13.7, 2.12.12]
+        scala: [2.13.7, 2.12.12, 3.4.0]
         java: [adopt@1.8]
     runs-on: ${{ matrix.os }}
     steps:
diff --git a/build.sbt b/build.sbt
index d440271..bc84835 100644
--- a/build.sbt
+++ b/build.sbt
@@ -1,5 +1,5 @@
 ThisBuild / organization := "io.circe"
-ThisBuild / crossScalaVersions := Seq("2.12.15", "2.13.6")
+ThisBuild / crossScalaVersions := Seq("2.12.15", "2.13.6", "3.4.0")
 ThisBuild / githubWorkflowPublishTargetBranches := Nil
 ThisBuild / githubWorkflowJobSetup := {
   (ThisBuild / githubWorkflowJobSetup).value.toList.map {
@@ -36,8 +36,9 @@ val previousCirceJsonSchemaVersion = "0.1.0"
 
 val scala212 = "2.12.12"
 val scala213 = "2.13.7"
+val scala3  = "3.4.0"
 
-ThisBuild / crossScalaVersions := Seq(scala213, scala212)
+ThisBuild / crossScalaVersions := Seq(scala213, scala212, scala3)
 
 def priorTo2_13(scalaVersion: String): Boolean =
   CrossVersion.partialVersion(scalaVersion) match {