diff --git a/buildSrc/build.gradle.kts b/buildSrc/build.gradle.kts
index 4ad61a8c3..a7c88377b 100644
--- a/buildSrc/build.gradle.kts
+++ b/buildSrc/build.gradle.kts
@@ -8,7 +8,7 @@ plugins {
 }
 
 dependencies {
-    implementation("org.jetbrains.kotlin:kotlin-gradle-plugin:1.3.72")
+    implementation("org.jetbrains.kotlin:kotlin-gradle-plugin:1.4.0-rc")
     implementation("org.jetbrains.dokka:dokka-gradle-plugin:0.10.1")
     implementation("com.android.tools.build:gradle:4.0.1")
 }
diff --git a/buildSrc/src/main/kotlin/Dependencies.kt b/buildSrc/src/main/kotlin/Dependencies.kt
index 9e2899dcd..f469d673e 100644
--- a/buildSrc/src/main/kotlin/Dependencies.kt
+++ b/buildSrc/src/main/kotlin/Dependencies.kt
@@ -1,7 +1,7 @@
 object Versions {
-    const val kotlin = "1.3.72"
-    const val serialization = "0.20.0"
-    const val atomicfu = "0.14.2"
+    const val kotlin = "1.4.0-rc"
+    const val serialization = "1.0-M1-1.4.0-rc"
+    const val atomicfu = "0.14.3-1.4.0-rc"
     const val androidxTest = "1.2.0"
     const val googleTruth = "1.0.1"
     const val kotlinpoet = "1.6.0"
@@ -10,14 +10,12 @@ object Versions {
 
 object Libs {
     object Serialization {
-        const val common = "org.jetbrains.kotlinx:kotlinx-serialization-runtime-common:${Versions.serialization}"
-        const val jvm = "org.jetbrains.kotlinx:kotlinx-serialization-runtime:${Versions.serialization}"
-        const val native = "org.jetbrains.kotlinx:kotlinx-serialization-runtime-native:${Versions.serialization}"
+        const val runtime = "org.jetbrains.kotlinx:kotlinx-serialization-runtime:${Versions.serialization}"
     }
 
     object AtomicFU {
         const val gradlePlugin = "org.jetbrains.kotlinx:atomicfu-gradle-plugin:${Versions.atomicfu}"
-        const val native = "org.jetbrains.kotlinx:atomicfu-native:${Versions.atomicfu}"
+        const val runtime = "org.jetbrains.kotlinx:atomicfu:${Versions.atomicfu}"
     }
 
     object AndroidxTest {
diff --git a/buildSrc/src/main/kotlin/multiplatform-library.gradle.kts b/buildSrc/src/main/kotlin/multiplatform-library.gradle.kts
index 8a88c62e4..c172b4bc8 100644
--- a/buildSrc/src/main/kotlin/multiplatform-library.gradle.kts
+++ b/buildSrc/src/main/kotlin/multiplatform-library.gradle.kts
@@ -45,12 +45,6 @@ kotlin {
             }
         }
     }
-
-    // Workaround for https://youtrack.jetbrains.com/issue/KT-36721
-    targets.withType<KotlinNativeTarget>().configureEach {
-        val moduleName = "${project.group}.${project.name}"
-        compilations["main"].kotlinOptions.freeCompilerArgs += listOf("-module-name", moduleName)
-    }
 }
 
 val emptySourcesJar by tasks.registering(Jar::class) {
diff --git a/core/build.gradle.kts b/core/build.gradle.kts
index 60c4f4e8a..a20b4fd78 100644
--- a/core/build.gradle.kts
+++ b/core/build.gradle.kts
@@ -14,10 +14,6 @@ kotlin {
     sourceSets {
         val commonMain by getting {
             kotlin.srcDirs("src/commonMain/generated")
-
-            dependencies {
-                implementation(kotlin("stdlib-common"))
-            }
         }
 
         val commonTest by getting {
@@ -27,12 +23,6 @@ kotlin {
             }
         }
 
-        val jvmMain by getting {
-            dependencies {
-                implementation(kotlin("stdlib-jdk8"))
-            }
-        }
-
         val jvmTest by getting {
             dependencies {
                 implementation(kotlin("test"))
@@ -43,7 +33,7 @@ kotlin {
 
         val darwinMain by getting {
             dependencies {
-                implementation(Libs.AtomicFU.native)
+                implementation(Libs.AtomicFU.runtime)
             }
         }
     }
diff --git a/core/src/darwinMain/kotlin/io/islandtime/zone/TimeZoneRules.kt b/core/src/darwinMain/kotlin/io/islandtime/zone/TimeZoneRules.kt
index 684036454..d53ee8318 100644
--- a/core/src/darwinMain/kotlin/io/islandtime/zone/TimeZoneRules.kt
+++ b/core/src/darwinMain/kotlin/io/islandtime/zone/TimeZoneRules.kt
@@ -124,7 +124,7 @@ private class DarwinTimeZoneRules(timeZone: NSTimeZone) : TimeZoneRules {
                 val offsetAfter = offsetAt(nextTransition)
                 val dateTimeBefore = nextTransition.toIslandDateTimeAt(offsetBefore)
 
-                this += DarwinTimeZoneOffsetTransition(dateTimeBefore, offsetBefore, offsetAfter)
+                add(DarwinTimeZoneOffsetTransition(dateTimeBefore, offsetBefore, offsetAfter))
 
                 currentDate = nextTransition
                 nextTransition = timeZone.nextDaylightSavingTimeTransitionAfterDate(currentDate)
diff --git a/extensions/parcelize/build.gradle.kts b/extensions/parcelize/build.gradle.kts
index 2b1eb1b15..adb587c45 100644
--- a/extensions/parcelize/build.gradle.kts
+++ b/extensions/parcelize/build.gradle.kts
@@ -27,7 +27,6 @@ dependencies {
     coreLibraryDesugaring(Libs.androidDesugarJdkLibs)
 
     implementation(project(":core"))
-    implementation(kotlin("stdlib-jdk8"))
 
     androidTestImplementation(Libs.AndroidxTest.runner)
     androidTestImplementation(Libs.googleTruth)
diff --git a/extensions/serialization/build.gradle.kts b/extensions/serialization/build.gradle.kts
index 6c822cf15..4f50dd4ae 100644
--- a/extensions/serialization/build.gradle.kts
+++ b/extensions/serialization/build.gradle.kts
@@ -8,8 +8,7 @@ kotlin {
         val commonMain by getting {
             dependencies {
                 implementation(project(":core"))
-                implementation(kotlin("stdlib-common"))
-                implementation(Libs.Serialization.common)
+                implementation(Libs.Serialization.runtime)
             }
         }
 
@@ -20,24 +19,11 @@ kotlin {
             }
         }
 
-        val jvmMain by getting {
-            dependencies {
-                implementation(kotlin("stdlib-jdk8"))
-                implementation(Libs.Serialization.jvm)
-            }
-        }
-
         val jvmTest by getting {
             dependencies {
                 implementation(kotlin("test"))
                 implementation(kotlin("test-junit"))
             }
         }
-
-        val darwinMain by getting {
-            dependencies {
-                implementation(Libs.Serialization.native)
-            }
-        }
     }
 }
\ No newline at end of file
diff --git a/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/Date.kt b/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/Date.kt
index 0b554f5bf..e976bf4b4 100644
--- a/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/Date.kt
+++ b/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/Date.kt
@@ -2,11 +2,16 @@ package io.islandtime.extensions.serialization
 
 import io.islandtime.Date
 import io.islandtime.toDate
-import kotlinx.serialization.*
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.descriptors.PrimitiveKind
+import kotlinx.serialization.descriptors.PrimitiveSerialDescriptor
+import kotlinx.serialization.descriptors.SerialDescriptor
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
 
 object DateSerializer : KSerializer<Date> {
     override val descriptor: SerialDescriptor =
-        PrimitiveDescriptor("io.islandtime.DateSerializer", PrimitiveKind.STRING)
+        PrimitiveSerialDescriptor("io.islandtime.DateSerializer", PrimitiveKind.STRING)
 
     override fun serialize(encoder: Encoder, value: Date) {
         encoder.encodeString(value.toString())
diff --git a/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/DateTime.kt b/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/DateTime.kt
index 7e4a93cc5..ffc732505 100644
--- a/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/DateTime.kt
+++ b/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/DateTime.kt
@@ -2,11 +2,16 @@ package io.islandtime.extensions.serialization
 
 import io.islandtime.DateTime
 import io.islandtime.toDateTime
-import kotlinx.serialization.*
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.descriptors.PrimitiveKind
+import kotlinx.serialization.descriptors.PrimitiveSerialDescriptor
+import kotlinx.serialization.descriptors.SerialDescriptor
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
 
 object DateTimeSerializer : KSerializer<DateTime> {
     override val descriptor: SerialDescriptor =
-        PrimitiveDescriptor("io.islandtime.DateTimeSerializer", PrimitiveKind.STRING)
+        PrimitiveSerialDescriptor("io.islandtime.DateTimeSerializer", PrimitiveKind.STRING)
 
     override fun serialize(encoder: Encoder, value: DateTime) {
         encoder.encodeString(value.toString())
diff --git a/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/Instant.kt b/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/Instant.kt
index 490343bc2..28cbb9192 100644
--- a/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/Instant.kt
+++ b/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/Instant.kt
@@ -2,11 +2,16 @@ package io.islandtime.extensions.serialization
 
 import io.islandtime.Instant
 import io.islandtime.toInstant
-import kotlinx.serialization.*
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.descriptors.PrimitiveKind
+import kotlinx.serialization.descriptors.PrimitiveSerialDescriptor
+import kotlinx.serialization.descriptors.SerialDescriptor
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
 
 object InstantSerializer : KSerializer<Instant> {
     override val descriptor: SerialDescriptor =
-        PrimitiveDescriptor("io.islandtime.InstantSerializer", PrimitiveKind.STRING)
+        PrimitiveSerialDescriptor("io.islandtime.InstantSerializer", PrimitiveKind.STRING)
 
     override fun serialize(encoder: Encoder, value: Instant) {
         encoder.encodeString(value.toString())
diff --git a/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/OffsetDateTime.kt b/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/OffsetDateTime.kt
index 66ed35560..858b17b13 100644
--- a/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/OffsetDateTime.kt
+++ b/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/OffsetDateTime.kt
@@ -2,11 +2,16 @@ package io.islandtime.extensions.serialization
 
 import io.islandtime.OffsetDateTime
 import io.islandtime.toOffsetDateTime
-import kotlinx.serialization.*
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.descriptors.PrimitiveKind
+import kotlinx.serialization.descriptors.PrimitiveSerialDescriptor
+import kotlinx.serialization.descriptors.SerialDescriptor
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
 
 object OffsetDateTimeSerializer : KSerializer<OffsetDateTime> {
     override val descriptor: SerialDescriptor =
-        PrimitiveDescriptor("io.islandtime.OffsetDateTimeSerializer", PrimitiveKind.STRING)
+        PrimitiveSerialDescriptor("io.islandtime.OffsetDateTimeSerializer", PrimitiveKind.STRING)
 
     override fun serialize(encoder: Encoder, value: OffsetDateTime) {
         encoder.encodeString(value.toString())
diff --git a/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/OffsetTime.kt b/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/OffsetTime.kt
index a98bff1bd..0053b2445 100644
--- a/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/OffsetTime.kt
+++ b/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/OffsetTime.kt
@@ -2,11 +2,16 @@ package io.islandtime.extensions.serialization
 
 import io.islandtime.OffsetTime
 import io.islandtime.toOffsetTime
-import kotlinx.serialization.*
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.descriptors.PrimitiveKind
+import kotlinx.serialization.descriptors.PrimitiveSerialDescriptor
+import kotlinx.serialization.descriptors.SerialDescriptor
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
 
 object OffsetTimeSerializer : KSerializer<OffsetTime> {
     override val descriptor: SerialDescriptor =
-        PrimitiveDescriptor("io.islandtime.OffsetTimeSerializer", PrimitiveKind.STRING)
+        PrimitiveSerialDescriptor("io.islandtime.OffsetTimeSerializer", PrimitiveKind.STRING)
 
     override fun serialize(encoder: Encoder, value: OffsetTime) {
         encoder.encodeString(value.toString())
diff --git a/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/Time.kt b/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/Time.kt
index 8b312f9ab..54a1a6dd9 100644
--- a/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/Time.kt
+++ b/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/Time.kt
@@ -2,11 +2,16 @@ package io.islandtime.extensions.serialization
 
 import io.islandtime.Time
 import io.islandtime.toTime
-import kotlinx.serialization.*
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.descriptors.PrimitiveKind
+import kotlinx.serialization.descriptors.PrimitiveSerialDescriptor
+import kotlinx.serialization.descriptors.SerialDescriptor
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
 
 object TimeSerializer : KSerializer<Time> {
     override val descriptor: SerialDescriptor =
-        PrimitiveDescriptor("io.islandtime.TimeSerializer", PrimitiveKind.STRING)
+        PrimitiveSerialDescriptor("io.islandtime.TimeSerializer", PrimitiveKind.STRING)
 
     override fun serialize(encoder: Encoder, value: Time) {
         encoder.encodeString(value.toString())
diff --git a/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/TimeZone.kt b/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/TimeZone.kt
index 59677073b..5419797eb 100644
--- a/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/TimeZone.kt
+++ b/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/TimeZone.kt
@@ -1,11 +1,16 @@
 package io.islandtime.extensions.serialization
 
 import io.islandtime.TimeZone
-import kotlinx.serialization.*
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.descriptors.PrimitiveKind
+import kotlinx.serialization.descriptors.PrimitiveSerialDescriptor
+import kotlinx.serialization.descriptors.SerialDescriptor
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
 
 object TimeZoneSerializer : KSerializer<TimeZone> {
     override val descriptor: SerialDescriptor =
-        PrimitiveDescriptor("io.islandtime.TimeZoneSerializer", PrimitiveKind.STRING)
+        PrimitiveSerialDescriptor("io.islandtime.TimeZoneSerializer", PrimitiveKind.STRING)
 
     override fun serialize(encoder: Encoder, value: TimeZone) {
         encoder.encodeString(value.toString())
diff --git a/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/YearMonth.kt b/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/YearMonth.kt
index 7c76695d5..356f93a96 100644
--- a/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/YearMonth.kt
+++ b/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/YearMonth.kt
@@ -2,11 +2,16 @@ package io.islandtime.extensions.serialization
 
 import io.islandtime.YearMonth
 import io.islandtime.toYearMonth
-import kotlinx.serialization.*
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.descriptors.PrimitiveKind
+import kotlinx.serialization.descriptors.PrimitiveSerialDescriptor
+import kotlinx.serialization.descriptors.SerialDescriptor
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
 
 object YearMonthSerializer : KSerializer<YearMonth> {
     override val descriptor: SerialDescriptor =
-        PrimitiveDescriptor("io.islandtime.YearMonthSerializer", PrimitiveKind.STRING)
+        PrimitiveSerialDescriptor("io.islandtime.YearMonthSerializer", PrimitiveKind.STRING)
 
     override fun serialize(encoder: Encoder, value: YearMonth) {
         encoder.encodeString(value.toString())
diff --git a/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/ZonedDateTime.kt b/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/ZonedDateTime.kt
index 1cb4599c5..b01b13fab 100644
--- a/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/ZonedDateTime.kt
+++ b/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/ZonedDateTime.kt
@@ -2,11 +2,16 @@ package io.islandtime.extensions.serialization
 
 import io.islandtime.ZonedDateTime
 import io.islandtime.toZonedDateTime
-import kotlinx.serialization.*
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.descriptors.PrimitiveKind
+import kotlinx.serialization.descriptors.PrimitiveSerialDescriptor
+import kotlinx.serialization.descriptors.SerialDescriptor
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
 
 object ZonedDateTimeSerializer : KSerializer<ZonedDateTime> {
     override val descriptor: SerialDescriptor =
-        PrimitiveDescriptor("io.islandtime.ZonedDateTimeSerializer", PrimitiveKind.STRING)
+        PrimitiveSerialDescriptor("io.islandtime.ZonedDateTimeSerializer", PrimitiveKind.STRING)
 
     override fun serialize(encoder: Encoder, value: ZonedDateTime) {
         encoder.encodeString(value.toString())
diff --git a/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/measures/Duration.kt b/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/measures/Duration.kt
index c7d94cb7c..606862465 100644
--- a/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/measures/Duration.kt
+++ b/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/measures/Duration.kt
@@ -1,11 +1,17 @@
 package io.islandtime.extensions.serialization.measures
 
-import io.islandtime.measures.*
-import kotlinx.serialization.*
+import io.islandtime.measures.Duration
+import io.islandtime.measures.toDuration
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.descriptors.PrimitiveKind
+import kotlinx.serialization.descriptors.PrimitiveSerialDescriptor
+import kotlinx.serialization.descriptors.SerialDescriptor
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
 
 object DurationSerializer : KSerializer<Duration> {
     override val descriptor: SerialDescriptor =
-        PrimitiveDescriptor("io.islandtime.measures.DurationSerializer", PrimitiveKind.STRING)
+        PrimitiveSerialDescriptor("io.islandtime.measures.DurationSerializer", PrimitiveKind.STRING)
 
     override fun serialize(encoder: Encoder, value: Duration) {
         encoder.encodeString(value.toString())
diff --git a/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/measures/Period.kt b/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/measures/Period.kt
index 410726c04..cf97454f4 100644
--- a/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/measures/Period.kt
+++ b/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/measures/Period.kt
@@ -1,11 +1,17 @@
 package io.islandtime.extensions.serialization.measures
 
-import io.islandtime.measures.*
-import kotlinx.serialization.*
+import io.islandtime.measures.Period
+import io.islandtime.measures.toPeriod
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.descriptors.PrimitiveKind
+import kotlinx.serialization.descriptors.PrimitiveSerialDescriptor
+import kotlinx.serialization.descriptors.SerialDescriptor
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
 
 object PeriodSerializer : KSerializer<Period> {
     override val descriptor: SerialDescriptor =
-        PrimitiveDescriptor("io.islandtime.measures.PeriodSerializer", PrimitiveKind.STRING)
+        PrimitiveSerialDescriptor("io.islandtime.measures.PeriodSerializer", PrimitiveKind.STRING)
 
     override fun serialize(encoder: Encoder, value: Period) {
         encoder.encodeString(value.toString())
diff --git a/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/ranges/DateRange.kt b/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/ranges/DateRange.kt
index c37c7eeaf..69d0ce2a1 100644
--- a/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/ranges/DateRange.kt
+++ b/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/ranges/DateRange.kt
@@ -2,11 +2,16 @@ package io.islandtime.extensions.serialization.ranges
 
 import io.islandtime.ranges.DateRange
 import io.islandtime.ranges.toDateRange
-import kotlinx.serialization.*
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.descriptors.PrimitiveKind
+import kotlinx.serialization.descriptors.PrimitiveSerialDescriptor
+import kotlinx.serialization.descriptors.SerialDescriptor
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
 
 object DateRangeSerializer : KSerializer<DateRange> {
     override val descriptor: SerialDescriptor =
-        PrimitiveDescriptor("io.islandtime.ranges.DateRangeSerializer", PrimitiveKind.STRING)
+        PrimitiveSerialDescriptor("io.islandtime.ranges.DateRangeSerializer", PrimitiveKind.STRING)
 
     override fun serialize(encoder: Encoder, value: DateRange) {
         encoder.encodeString(value.toString())
diff --git a/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/ranges/DateTimeInterval.kt b/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/ranges/DateTimeInterval.kt
index 0e56481a7..e89d7d1cc 100644
--- a/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/ranges/DateTimeInterval.kt
+++ b/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/ranges/DateTimeInterval.kt
@@ -2,11 +2,16 @@ package io.islandtime.extensions.serialization.ranges
 
 import io.islandtime.ranges.DateTimeInterval
 import io.islandtime.ranges.toDateTimeInterval
-import kotlinx.serialization.*
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.descriptors.PrimitiveKind
+import kotlinx.serialization.descriptors.PrimitiveSerialDescriptor
+import kotlinx.serialization.descriptors.SerialDescriptor
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
 
 object DateTimeIntervalSerializer : KSerializer<DateTimeInterval> {
     override val descriptor: SerialDescriptor =
-        PrimitiveDescriptor("io.islandtime.ranges.DateTimeIntervalSerializer", PrimitiveKind.STRING)
+        PrimitiveSerialDescriptor("io.islandtime.ranges.DateTimeIntervalSerializer", PrimitiveKind.STRING)
 
     override fun serialize(encoder: Encoder, value: DateTimeInterval) {
         encoder.encodeString(value.toString())
diff --git a/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/ranges/InstantInterval.kt b/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/ranges/InstantInterval.kt
index d35a1fa9c..919d3e0b4 100644
--- a/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/ranges/InstantInterval.kt
+++ b/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/ranges/InstantInterval.kt
@@ -2,11 +2,16 @@ package io.islandtime.extensions.serialization.ranges
 
 import io.islandtime.ranges.InstantInterval
 import io.islandtime.ranges.toInstantInterval
-import kotlinx.serialization.*
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.descriptors.PrimitiveKind
+import kotlinx.serialization.descriptors.PrimitiveSerialDescriptor
+import kotlinx.serialization.descriptors.SerialDescriptor
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
 
 object InstantIntervalSerializer : KSerializer<InstantInterval> {
     override val descriptor: SerialDescriptor =
-        PrimitiveDescriptor("io.islandtime.ranges.InstantIntervalSerializer", PrimitiveKind.STRING)
+        PrimitiveSerialDescriptor("io.islandtime.ranges.InstantIntervalSerializer", PrimitiveKind.STRING)
 
     override fun serialize(encoder: Encoder, value: InstantInterval) {
         encoder.encodeString(value.toString())
diff --git a/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/ranges/OffsetDateTimeInterval.kt b/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/ranges/OffsetDateTimeInterval.kt
index 48745140b..9ac411674 100644
--- a/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/ranges/OffsetDateTimeInterval.kt
+++ b/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/ranges/OffsetDateTimeInterval.kt
@@ -2,11 +2,16 @@ package io.islandtime.extensions.serialization.ranges
 
 import io.islandtime.ranges.OffsetDateTimeInterval
 import io.islandtime.ranges.toOffsetDateTimeInterval
-import kotlinx.serialization.*
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.descriptors.PrimitiveKind
+import kotlinx.serialization.descriptors.PrimitiveSerialDescriptor
+import kotlinx.serialization.descriptors.SerialDescriptor
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
 
 object OffsetDateTimeIntervalSerializer : KSerializer<OffsetDateTimeInterval> {
     override val descriptor: SerialDescriptor =
-        PrimitiveDescriptor("io.islandtime.OffsetDateTimeIntervalSerializer", PrimitiveKind.STRING)
+        PrimitiveSerialDescriptor("io.islandtime.OffsetDateTimeIntervalSerializer", PrimitiveKind.STRING)
 
     override fun serialize(encoder: Encoder, value: OffsetDateTimeInterval) {
         encoder.encodeString(value.toString())
diff --git a/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/ranges/ZonedDateTimeInterval.kt b/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/ranges/ZonedDateTimeInterval.kt
index 3e5d80232..fc5eb1a77 100644
--- a/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/ranges/ZonedDateTimeInterval.kt
+++ b/extensions/serialization/src/commonMain/kotlin/io/islandtime/extensions/serialization/ranges/ZonedDateTimeInterval.kt
@@ -2,11 +2,16 @@ package io.islandtime.extensions.serialization.ranges
 
 import io.islandtime.ranges.ZonedDateTimeInterval
 import io.islandtime.ranges.toZonedDateTimeInterval
-import kotlinx.serialization.*
+import kotlinx.serialization.KSerializer
+import kotlinx.serialization.descriptors.PrimitiveKind
+import kotlinx.serialization.descriptors.PrimitiveSerialDescriptor
+import kotlinx.serialization.descriptors.SerialDescriptor
+import kotlinx.serialization.encoding.Decoder
+import kotlinx.serialization.encoding.Encoder
 
 object ZonedDateTimeIntervalSerializer : KSerializer<ZonedDateTimeInterval> {
     override val descriptor: SerialDescriptor =
-        PrimitiveDescriptor("io.islandtime.ZonedDateTimeIntervalSerializer", PrimitiveKind.STRING)
+        PrimitiveSerialDescriptor("io.islandtime.ZonedDateTimeIntervalSerializer", PrimitiveKind.STRING)
 
     override fun serialize(encoder: Encoder, value: ZonedDateTimeInterval) {
         encoder.encodeString(value.toString())
diff --git a/extensions/serialization/src/commonTest/kotlin/io/islandtime/extensions/serialization/SerializerTest.kt b/extensions/serialization/src/commonTest/kotlin/io/islandtime/extensions/serialization/SerializerTest.kt
index 8f5ce3242..ed857004b 100644
--- a/extensions/serialization/src/commonTest/kotlin/io/islandtime/extensions/serialization/SerializerTest.kt
+++ b/extensions/serialization/src/commonTest/kotlin/io/islandtime/extensions/serialization/SerializerTest.kt
@@ -6,58 +6,56 @@ import io.islandtime.extensions.serialization.measures.PeriodSerializer
 import io.islandtime.extensions.serialization.ranges.*
 import io.islandtime.measures.*
 import io.islandtime.ranges.*
-import kotlinx.serialization.ContextualSerialization
+import kotlinx.serialization.Contextual
+import kotlinx.serialization.Polymorphic
 import kotlinx.serialization.Serializable
 import kotlinx.serialization.json.Json
-import kotlinx.serialization.json.JsonConfiguration
-import kotlinx.serialization.modules.serializersModuleOf
+import kotlinx.serialization.modules.SerializersModule
+import kotlinx.serialization.modules.contextual
+import kotlinx.serialization.modules.polymorphic
+import kotlinx.serialization.modules.subclass
 import kotlin.test.Test
 import kotlin.test.assertEquals
 
 @Serializable
 data class TestData(
-    @ContextualSerialization val date: Date,
-    @ContextualSerialization val time: Time,
-    @ContextualSerialization val dateTime: DateTime,
-    @ContextualSerialization val offsetTime: OffsetTime,
-    @ContextualSerialization val offsetDateTime: OffsetDateTime,
-    @ContextualSerialization val zonedDateTime: ZonedDateTime,
-    @ContextualSerialization val yearMonth: YearMonth,
-    @ContextualSerialization val instant: Instant,
-    @ContextualSerialization val zoneRegion: TimeZone,
-    @ContextualSerialization val fixedZone: TimeZone,
-    @ContextualSerialization val duration: Duration,
-    @ContextualSerialization val period: Period,
-    @ContextualSerialization val dateRange: DateRange,
-    @ContextualSerialization val dateTimeInterval: DateTimeInterval,
-    @ContextualSerialization val instantInterval: InstantInterval,
-    @ContextualSerialization val offsetDateTimeInterval: OffsetDateTimeInterval,
-    @ContextualSerialization val zonedDateTimeInterval: ZonedDateTimeInterval
+    @Contextual val date: Date,
+    @Contextual val time: Time,
+    @Contextual val dateTime: DateTime,
+    @Contextual val offsetTime: OffsetTime,
+    @Contextual val offsetDateTime: OffsetDateTime,
+    @Contextual val zonedDateTime: ZonedDateTime,
+    @Contextual val yearMonth: YearMonth,
+    @Contextual val instant: Instant,
+    @Serializable(with = TimeZoneSerializer::class) val zoneRegion: TimeZone,
+    @Serializable(with = TimeZoneSerializer::class) val fixedZone: TimeZone,
+    @Contextual val duration: Duration,
+    @Contextual val period: Period,
+    @Contextual val dateRange: DateRange,
+    @Contextual val dateTimeInterval: DateTimeInterval,
+    @Contextual val instantInterval: InstantInterval,
+    @Contextual val offsetDateTimeInterval: OffsetDateTimeInterval,
+    @Contextual val zonedDateTimeInterval: ZonedDateTimeInterval
 )
 
 class SerializerTest {
-    private val stringModule = serializersModuleOf(
-        mapOf(
-            Date::class to DateSerializer,
-            Time::class to TimeSerializer,
-            DateTime::class to DateTimeSerializer,
-            OffsetTime::class to OffsetTimeSerializer,
-            OffsetDateTime::class to OffsetDateTimeSerializer,
-            ZonedDateTime::class to ZonedDateTimeSerializer,
-            YearMonth::class to YearMonthSerializer,
-            Instant::class to InstantSerializer,
-            TimeZone::class to TimeZoneSerializer,
-            TimeZone.Region::class to TimeZoneSerializer,
-            TimeZone.FixedOffset::class to TimeZoneSerializer,
-            Duration::class to DurationSerializer,
-            Period::class to PeriodSerializer,
-            DateRange::class to DateRangeSerializer,
-            DateTimeInterval::class to DateTimeIntervalSerializer,
-            InstantInterval::class to InstantIntervalSerializer,
-            OffsetDateTimeInterval::class to OffsetDateTimeIntervalSerializer,
-            ZonedDateTimeInterval::class to ZonedDateTimeIntervalSerializer
-        )
-    )
+    private val stringModule = SerializersModule {
+        contextual(DateSerializer)
+        contextual(TimeSerializer)
+        contextual(DateTimeSerializer)
+        contextual(OffsetTimeSerializer)
+        contextual(OffsetDateTimeSerializer)
+        contextual(ZonedDateTimeSerializer)
+        contextual(YearMonthSerializer)
+        contextual(InstantSerializer)
+        contextual(DurationSerializer)
+        contextual(PeriodSerializer)
+        contextual(DateRangeSerializer)
+        contextual(DateTimeIntervalSerializer)
+        contextual(InstantIntervalSerializer)
+        contextual(OffsetDateTimeIntervalSerializer)
+        contextual(ZonedDateTimeIntervalSerializer)
+    }
 
     private val testData = TestData(
         date = Date(2018, Month.FEBRUARY, 21),
@@ -87,7 +85,7 @@ class SerializerTest {
         yearMonth = YearMonth(2019, Month.FEBRUARY),
         instant = Instant(1L.seconds, 1.nanoseconds),
         zoneRegion = TimeZone("America/Non_Existent_Zone"),
-        fixedZone = TimeZone.FixedOffset("+04:30"),
+        fixedZone = TimeZone("+04:30"),
         duration = durationOf(1.seconds, 500.nanoseconds),
         period = periodOf(1.years, 2.months, 3.days),
         dateRange = "2019-01-01/2019-05-31".toDateRange(),
@@ -100,8 +98,11 @@ class SerializerTest {
 
     @Test
     fun `serialize and unserialize to json`() {
-        val json = Json(JsonConfiguration.Stable.copy(prettyPrint = true), stringModule)
-        val text = json.stringify(TestData.serializer(), testData)
+        val json = Json {
+            prettyPrint = true
+            serializersModule = stringModule
+        }
+        val text = json.encodeToString(TestData.serializer(), testData)
 
         assertEquals(
             """
@@ -128,7 +129,7 @@ class SerializerTest {
             text
         )
 
-        val parsedTestData = json.parse(TestData.serializer(), text)
+        val parsedTestData = json.decodeFromString(TestData.serializer(), text)
         assertEquals(testData, parsedTestData)
     }
 }
\ No newline at end of file
diff --git a/gradle.properties b/gradle.properties
index 0396bde2a..e15ad36a7 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -14,7 +14,8 @@ snapshotRepositoryUrl=https://oss.sonatype.org/content/repositories/snapshots
 releaseRepositoryUrl=https://oss.sonatype.org/service/local/staging/deploy/maven2
 
 kotlin.code.style=official
-kotlin.native.disableCompilerDaemon=true
+kotlin.mpp.enableGranularSourceSetsMetadata=true
+kotlin.mpp.enableCompatibilityMetadataVariant=true
 
 org.gradle.parallel=true
 org.gradle.jvmargs=-Xmx4096M
diff --git a/settings.gradle.kts b/settings.gradle.kts
index 595b0c812..7d02aeb37 100644
--- a/settings.gradle.kts
+++ b/settings.gradle.kts
@@ -1,3 +1,10 @@
+pluginManagement {
+    repositories {
+        maven(url = "https://dl.bintray.com/kotlin/kotlin-eap")
+        gradlePluginPortal()
+    }
+}
+
 include(
     ":core",
     ":tools:code-generator",
diff --git a/tools/code-generator/build.gradle.kts b/tools/code-generator/build.gradle.kts
index 482e6a14b..566bb0a0e 100644
--- a/tools/code-generator/build.gradle.kts
+++ b/tools/code-generator/build.gradle.kts
@@ -4,7 +4,6 @@ plugins {
 }
 
 dependencies {
-    implementation(kotlin("stdlib-jdk8"))
     implementation(Libs.kotlinpoet)
 }