diff --git a/gradle/libs.versions.toml b/gradle/libs.versions.toml
index f66e32b..e092775 100644
--- a/gradle/libs.versions.toml
+++ b/gradle/libs.versions.toml
@@ -19,7 +19,7 @@ incap = "0.3"
 jvmTarget = "1.8"
 kotlin = "1.5.21"
 kotlinCompileTesting = "1.4.3"
-kotlinpoet = "1.9.0"
+kotlinpoet = "1.10.0"
 ktlint = "0.41.0"
 
 [plugins]
@@ -34,15 +34,14 @@ asm = "org.ow2.asm:asm:9.2"
 autoCommon = "com.google.auto:auto-common:1.1"
 autoService = { module = "com.google.auto.service:auto-service-annotations", version.ref = "autoService" }
 autoService-processor = { module = "com.google.auto.service:auto-service", version.ref = "autoService" }
+guava = { module = "com.google.guava:guava", version = "30.1.1-jre" }
 incap = { module = "net.ltgt.gradle.incap:incap", version.ref = "incap" }
 incap-processor = { module = "net.ltgt.gradle.incap:incap-processor", version.ref = "incap" }
 jsr305 = "com.google.code.findbugs:jsr305:3.0.2"
 kotlin-compilerEmbeddable = { module = "org.jetbrains.kotlin:kotlin-compiler-embeddable", version.ref = "kotlin" }
 kotlin-reflect = { module = "org.jetbrains.kotlin:kotlin-reflect", version.ref = "kotlin" }
 kotlinpoet = { module = "com.squareup:kotlinpoet", version.ref = "kotlinpoet" }
-kotlinpoet-elementsClassInspector = { module = "com.squareup:kotlinpoet-classinspector-elements", version.ref = "kotlinpoet" }
-kotlinpoet-metadata-core = { module = "com.squareup:kotlinpoet-metadata", version.ref = "kotlinpoet" }
-kotlinpoet-metadata-specs = { module = "com.squareup:kotlinpoet-metadata-specs", version.ref = "kotlinpoet" }
+kotlinpoet-metadata = { module = "com.squareup:kotlinpoet-metadata", version.ref = "kotlinpoet" }
 kotlinxMetadata = "org.jetbrains.kotlinx:kotlinx-metadata-jvm:0.3.0"
 okio = "com.squareup.okio:okio:2.10.0"
 
diff --git a/kotlin/codegen/build.gradle.kts b/kotlin/codegen/build.gradle.kts
index 4a9389f..67a3544 100644
--- a/kotlin/codegen/build.gradle.kts
+++ b/kotlin/codegen/build.gradle.kts
@@ -62,20 +62,12 @@ dependencies {
     exclude(group = "org.jetbrains.kotlin", module = "kotlin-stdlib")
   }
   api(libs.kotlinpoet)
-  shade(libs.kotlinpoet.metadata.core) {
-    exclude(group = "org.jetbrains.kotlin")
-    exclude(group = "com.squareup", module = "kotlinpoet")
-  }
-  shade(libs.kotlinpoet.metadata.specs) {
-    exclude(group = "org.jetbrains.kotlin")
-    exclude(group = "com.squareup", module = "kotlinpoet")
-  }
-  api(libs.kotlinpoet.elementsClassInspector)
-  shade(libs.kotlinpoet.elementsClassInspector) {
+  shade(libs.kotlinpoet.metadata) {
     exclude(group = "org.jetbrains.kotlin")
     exclude(group = "com.squareup", module = "kotlinpoet")
     exclude(group = "com.google.guava")
   }
+  api(libs.guava)
   api(libs.asm)
 
   api(libs.autoService)
@@ -84,9 +76,7 @@ dependencies {
   kapt(libs.incap.processor)
 
   // Copy these again as they're not automatically included since they're shaded
-  testImplementation(libs.kotlinpoet.metadata.core)
-  testImplementation(libs.kotlinpoet.metadata.specs)
-  testImplementation(libs.kotlinpoet.elementsClassInspector)
+  testImplementation(libs.kotlinpoet.metadata)
   testImplementation(libs.junit)
   testImplementation(libs.truth)
   testImplementation(libs.kotlinCompileTesting)
diff --git a/kotlin/codegen/src/main/java/com/squareup/moshi/kotlin/codegen/apt/JsonClassCodegenProcessor.kt b/kotlin/codegen/src/main/java/com/squareup/moshi/kotlin/codegen/apt/JsonClassCodegenProcessor.kt
index e2bb823..7ed9beb 100644
--- a/kotlin/codegen/src/main/java/com/squareup/moshi/kotlin/codegen/apt/JsonClassCodegenProcessor.kt
+++ b/kotlin/codegen/src/main/java/com/squareup/moshi/kotlin/codegen/apt/JsonClassCodegenProcessor.kt
@@ -18,7 +18,7 @@ package com.squareup.moshi.kotlin.codegen.apt
 import com.google.auto.service.AutoService
 import com.squareup.kotlinpoet.AnnotationSpec
 import com.squareup.kotlinpoet.ClassName
-import com.squareup.kotlinpoet.classinspector.elements.ElementsClassInspector
+import com.squareup.kotlinpoet.metadata.classinspectors.ElementsClassInspector
 import com.squareup.moshi.JsonClass
 import com.squareup.moshi.kotlin.codegen.api.AdapterGenerator
 import com.squareup.moshi.kotlin.codegen.api.PropertyGenerator
diff --git a/kotlin/codegen/src/main/java/com/squareup/moshi/kotlin/codegen/apt/MoshiCachedClassInspector.kt b/kotlin/codegen/src/main/java/com/squareup/moshi/kotlin/codegen/apt/MoshiCachedClassInspector.kt
index 756c4e4..f893921 100644
--- a/kotlin/codegen/src/main/java/com/squareup/moshi/kotlin/codegen/apt/MoshiCachedClassInspector.kt
+++ b/kotlin/codegen/src/main/java/com/squareup/moshi/kotlin/codegen/apt/MoshiCachedClassInspector.kt
@@ -16,12 +16,16 @@
 package com.squareup.moshi.kotlin.codegen.apt
 
 import com.squareup.kotlinpoet.TypeSpec
-import com.squareup.kotlinpoet.metadata.ImmutableKmClass
 import com.squareup.kotlinpoet.metadata.specs.ClassInspector
 import com.squareup.kotlinpoet.metadata.specs.toTypeSpec
-import com.squareup.kotlinpoet.metadata.toImmutableKmClass
+import com.squareup.kotlinpoet.metadata.toKmClass
+import kotlinx.metadata.KmClass
+import java.util.TreeMap
 import javax.lang.model.element.TypeElement
 
+/** KmClass doesn't implement equality natively. */
+private val KmClassComparator = compareBy<KmClass> { it.name }
+
 /**
  * This cached API over [ClassInspector] that caches certain lookups Moshi does potentially multiple
  * times. This is useful mostly because it avoids duplicate reloads in cases like common base
@@ -29,16 +33,16 @@ import javax.lang.model.element.TypeElement
  */
 internal class MoshiCachedClassInspector(private val classInspector: ClassInspector) {
   private val elementToSpecCache = mutableMapOf<TypeElement, TypeSpec>()
-  private val kmClassToSpecCache = mutableMapOf<ImmutableKmClass, TypeSpec>()
-  private val metadataToKmClassCache = mutableMapOf<Metadata, ImmutableKmClass>()
+  private val kmClassToSpecCache = TreeMap<KmClass, TypeSpec>(KmClassComparator)
+  private val metadataToKmClassCache = mutableMapOf<Metadata, KmClass>()
 
-  fun toImmutableKmClass(metadata: Metadata): ImmutableKmClass {
+  fun toKmClass(metadata: Metadata): KmClass {
     return metadataToKmClassCache.getOrPut(metadata) {
-      metadata.toImmutableKmClass()
+      metadata.toKmClass()
     }
   }
 
-  fun toTypeSpec(kmClass: ImmutableKmClass): TypeSpec {
+  fun toTypeSpec(kmClass: KmClass): TypeSpec {
     return kmClassToSpecCache.getOrPut(kmClass) {
       kmClass.toTypeSpec(classInspector)
     }
@@ -46,7 +50,7 @@ internal class MoshiCachedClassInspector(private val classInspector: ClassInspec
 
   fun toTypeSpec(element: TypeElement): TypeSpec {
     return elementToSpecCache.getOrPut(element) {
-      toTypeSpec(toImmutableKmClass(element.metadata))
+      toTypeSpec(toKmClass(element.metadata))
     }
   }
 }
diff --git a/kotlin/codegen/src/main/java/com/squareup/moshi/kotlin/codegen/apt/metadata.kt b/kotlin/codegen/src/main/java/com/squareup/moshi/kotlin/codegen/apt/metadata.kt
index 67015c4..bfd3012 100644
--- a/kotlin/codegen/src/main/java/com/squareup/moshi/kotlin/codegen/apt/metadata.kt
+++ b/kotlin/codegen/src/main/java/com/squareup/moshi/kotlin/codegen/apt/metadata.kt
@@ -27,7 +27,6 @@ import com.squareup.kotlinpoet.TypeVariableName
 import com.squareup.kotlinpoet.WildcardTypeName
 import com.squareup.kotlinpoet.asClassName
 import com.squareup.kotlinpoet.asTypeName
-import com.squareup.kotlinpoet.metadata.ImmutableKmConstructor
 import com.squareup.kotlinpoet.metadata.KotlinPoetMetadataPreview
 import com.squareup.kotlinpoet.metadata.isAbstract
 import com.squareup.kotlinpoet.metadata.isClass
@@ -37,8 +36,8 @@ import com.squareup.kotlinpoet.metadata.isInternal
 import com.squareup.kotlinpoet.metadata.isLocal
 import com.squareup.kotlinpoet.metadata.isPublic
 import com.squareup.kotlinpoet.metadata.isSealed
-import com.squareup.kotlinpoet.metadata.specs.TypeNameAliasTag
 import com.squareup.kotlinpoet.tag
+import com.squareup.kotlinpoet.tags.TypeAliasTag
 import com.squareup.moshi.Json
 import com.squareup.moshi.JsonQualifier
 import com.squareup.moshi.kotlin.codegen.api.DelegateKey
@@ -49,6 +48,8 @@ import com.squareup.moshi.kotlin.codegen.api.TargetProperty
 import com.squareup.moshi.kotlin.codegen.api.TargetType
 import com.squareup.moshi.kotlin.codegen.api.deepCopy
 import com.squareup.moshi.kotlin.codegen.api.rawType
+import kotlinx.metadata.KmConstructor
+import kotlinx.metadata.jvm.signature
 import java.lang.annotation.ElementType
 import java.lang.annotation.Retention
 import java.lang.annotation.RetentionPolicy
@@ -101,7 +102,7 @@ internal fun primaryConstructor(
     )
   }
 
-  val kmConstructorSignature = primaryConstructor.tag<ImmutableKmConstructor>()?.signature?.toString()
+  val kmConstructorSignature = primaryConstructor.tag<KmConstructor>()?.signature?.toString()
     ?: run {
       messager.printMessage(
         ERROR,
@@ -138,7 +139,7 @@ internal fun targetType(
   }
 
   val kmClass = try {
-    cachedClassInspector.toImmutableKmClass(typeMetadata)
+    cachedClassInspector.toKmClass(typeMetadata)
   } catch (e: UnsupportedOperationException) {
     messager.printMessage(
       ERROR,
@@ -173,7 +174,7 @@ internal fun targetType(
       )
       return null
     }
-    kmClass.isSealed -> {
+    kmClass.flags.isSealed -> {
       messager.printMessage(
         ERROR,
         "@JsonClass can't be applied to $element: must not be sealed",
@@ -181,7 +182,7 @@ internal fun targetType(
       )
       return null
     }
-    kmClass.isAbstract -> {
+    kmClass.flags.isAbstract -> {
       messager.printMessage(
         ERROR,
         "@JsonClass can't be applied to $element: must not be abstract",
@@ -189,7 +190,7 @@ internal fun targetType(
       )
       return null
     }
-    kmClass.isLocal -> {
+    kmClass.flags.isLocal -> {
       messager.printMessage(
         ERROR,
         "@JsonClass can't be applied to $element: must not be local",
@@ -197,7 +198,7 @@ internal fun targetType(
       )
       return null
     }
-    !kmClass.isPublic && !kmClass.isInternal -> {
+    !kmClass.flags.isPublic && !kmClass.flags.isInternal -> {
       messager.printMessage(
         ERROR,
         "@JsonClass can't be applied to $element: must be internal or public",
@@ -311,8 +312,8 @@ internal fun targetType(
     // Implicitly public, so now look up the hierarchy
     val forceInternal = generateSequence<Element>(element) { it.enclosingElement }
       .filterIsInstance<TypeElement>()
-      .map { cachedClassInspector.toImmutableKmClass(it.metadata) }
-      .any { it.isInternal }
+      .map { cachedClassInspector.toKmClass(it.metadata) }
+      .any { it.flags.isInternal }
     if (forceInternal) KModifier.INTERNAL else visibility
   }
 
@@ -518,7 +519,7 @@ private fun String.escapeDollarSigns(): String {
 internal fun TypeName.unwrapTypeAlias(): TypeName {
   return when (this) {
     is ClassName -> {
-      tag<TypeNameAliasTag>()?.type?.let { unwrappedType ->
+      tag<TypeAliasTag>()?.abbreviatedType?.let { unwrappedType ->
         // If any type is nullable, then the whole thing is nullable
         var isAnyNullable = isNullable
         // Keep track of all annotations across type levels. Sort them too for consistency.