diff --git a/CHANGELOG.md b/CHANGELOG.md
index 468e2591..4905447d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,30 @@
 Changelog
 =========
 
+Version 0.21.0
+--------------
+
+_2022-12-28_
+
+#### **New:** Update to Kotlin `1.8.0`.
+- For moshi-ir, this release is only compatible with Kotlin 1.8 or later.
+- Migrate the IR and FIR plugins to new `CompilerPluginRegistrar` entrypoint API.
+
+#### **New:** Experimental support for the new K2 compiler in moshi-ir.
+
+Note this comes with several caveats:
+- There is no FIR plugin in moshi-ir itself (not needed). This just marks itself as compatible with the new compiler and avoids using incompatible IR APIs.
+- This only works if proguard rule generation is disabled, as there is no support in FIR currently for generating files.
+- K2 compiler itself is extremely experimental.
+
+In short, this is only really to unblock anyone doing their own testing of K2 and don't want this
+plugin to disable it. If you see any issues, please file a bug here and disable K2 in your project
+in the meantime.
+
+#### Misc
+- Update JVM target to `11`.
+- Update Anvil `compiler-utils` to `2.4.3`.
+
 Version 0.20.0
 --------------
 
diff --git a/gradle.properties b/gradle.properties
index 91f31589..5128a48f 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -18,7 +18,7 @@
 org.gradle.jvmargs=-Xmx2048m -Dfile.encoding=UTF-8
 
 GROUP=dev.zacsweers.moshix
-VERSION_NAME=0.21.0-SNAPSHOT
+VERSION_NAME=0.21.0
 POM_DESCRIPTION=Moshi Extensions
 POM_URL=https://github.com/ZacSweers/MoshiX
 POM_SCM_URL=https://github.com/ZacSweers/MoshiX
diff --git a/moshi-ir/moshi-gradle-plugin/gradle.properties b/moshi-ir/moshi-gradle-plugin/gradle.properties
index e477596e..908862c3 100644
--- a/moshi-ir/moshi-gradle-plugin/gradle.properties
+++ b/moshi-ir/moshi-gradle-plugin/gradle.properties
@@ -3,7 +3,7 @@ POM_ARTIFACT_ID=moshi-gradle-plugin
 POM_PACKAGING=jar
 
 GROUP=dev.zacsweers.moshix
-VERSION_NAME=0.21.0-SNAPSHOT
+VERSION_NAME=0.21.0
 POM_DESCRIPTION=A Kotlin compiler plugin that generates Moshi JsonAdapter classes.
 POM_URL=https://github.com/ZacSweers/MoshiX/
 POM_SCM_URL=https://github.com/ZacSweers/MoshiX/