diff --git a/okcurl/build.gradle.kts b/okcurl/build.gradle.kts
index 68801c91a201..7580ada125d1 100644
--- a/okcurl/build.gradle.kts
+++ b/okcurl/build.gradle.kts
@@ -1,7 +1,6 @@
 import com.android.build.gradle.internal.tasks.factory.dependsOn
 import com.vanniktech.maven.publish.JavadocJar
 import com.vanniktech.maven.publish.KotlinJvm
-import java.nio.charset.StandardCharsets
 import org.apache.tools.ant.taskdefs.condition.Os
 
 plugins {
@@ -69,7 +68,7 @@ tasks.register<Copy>("copyResourcesTemplates") {
   from("src/main/resources-templates")
   into("$buildDir/generated/resources-templates")
   expand("projectVersion" to "${project.version}")
-  filteringCharset = StandardCharsets.UTF_8.toString()
+  filteringCharset = Charsets.UTF_8.toString()
 }.let {
   tasks.processResources.dependsOn(it)
   tasks["javaSourcesJar"].dependsOn(it)
diff --git a/okhttp-dnsoverhttps/src/main/kotlin/okhttp3/dnsoverhttps/DnsRecordCodec.kt b/okhttp-dnsoverhttps/src/main/kotlin/okhttp3/dnsoverhttps/DnsRecordCodec.kt
index 62c679219639..367898be6488 100644
--- a/okhttp-dnsoverhttps/src/main/kotlin/okhttp3/dnsoverhttps/DnsRecordCodec.kt
+++ b/okhttp-dnsoverhttps/src/main/kotlin/okhttp3/dnsoverhttps/DnsRecordCodec.kt
@@ -18,7 +18,6 @@ package okhttp3.dnsoverhttps
 import java.io.EOFException
 import java.net.InetAddress
 import java.net.UnknownHostException
-import java.nio.charset.StandardCharsets
 import okio.Buffer
 import okio.ByteString
 import okio.utf8Size
@@ -32,7 +31,7 @@ object DnsRecordCodec {
   const val TYPE_A = 0x0001
   const val TYPE_AAAA = 0x001c
   private const val TYPE_PTR = 0x000c
-  private val ASCII = StandardCharsets.US_ASCII
+  private val ASCII = Charsets.US_ASCII
 
   fun encodeQuery(host: String, type: Int): ByteString = Buffer().apply {
     writeShort(0) // query id
diff --git a/okhttp-logging-interceptor/src/main/kotlin/okhttp3/logging/HttpLoggingInterceptor.kt b/okhttp-logging-interceptor/src/main/kotlin/okhttp3/logging/HttpLoggingInterceptor.kt
index 0529b05d77e7..196585812297 100644
--- a/okhttp-logging-interceptor/src/main/kotlin/okhttp3/logging/HttpLoggingInterceptor.kt
+++ b/okhttp-logging-interceptor/src/main/kotlin/okhttp3/logging/HttpLoggingInterceptor.kt
@@ -17,9 +17,9 @@ package okhttp3.logging
 
 import java.io.IOException
 import java.nio.charset.Charset
-import java.nio.charset.StandardCharsets.UTF_8
 import java.util.TreeSet
 import java.util.concurrent.TimeUnit
+import kotlin.text.Charsets.UTF_8
 import okhttp3.Headers
 import okhttp3.Interceptor
 import okhttp3.OkHttpClient
diff --git a/okhttp/build.gradle.kts b/okhttp/build.gradle.kts
index 86ca62736889..b9b7023db9bd 100644
--- a/okhttp/build.gradle.kts
+++ b/okhttp/build.gradle.kts
@@ -1,7 +1,6 @@
 import com.android.build.gradle.internal.tasks.factory.dependsOn
 import com.vanniktech.maven.publish.JavadocJar
 import com.vanniktech.maven.publish.KotlinMultiplatform
-import java.nio.charset.StandardCharsets
 import me.champeau.gradle.japicmp.JapicmpTask
 import org.jetbrains.kotlin.gradle.dsl.KotlinCompile
 
@@ -246,7 +245,7 @@ val copyKotlinTemplates = tasks.register<Copy>("copyKotlinTemplates") {
   from("src/commonMain/kotlinTemplates")
   into("$buildDir/generated/sources/kotlinTemplates")
   expand("projectVersion" to project.version)
-  filteringCharset = StandardCharsets.UTF_8.toString()
+  filteringCharset = Charsets.UTF_8.toString()
 }
 tasks.withType<KotlinCompile<*>> {
   dependsOn(copyKotlinTemplates)
diff --git a/okhttp/src/jvmMain/kotlin/okhttp3/Challenge.kt b/okhttp/src/jvmMain/kotlin/okhttp3/Challenge.kt
index bfd738acdd22..49b1f3eece12 100644
--- a/okhttp/src/jvmMain/kotlin/okhttp3/Challenge.kt
+++ b/okhttp/src/jvmMain/kotlin/okhttp3/Challenge.kt
@@ -16,10 +16,10 @@
 package okhttp3
 
 import java.nio.charset.Charset
-import java.nio.charset.StandardCharsets.ISO_8859_1
 import java.util.Collections.singletonMap
 import java.util.Collections.unmodifiableMap
 import java.util.Locale.US
+import kotlin.text.Charsets.ISO_8859_1
 
 /**
  * An [RFC 7235][rfc_7235] challenge.
diff --git a/okhttp/src/jvmMain/kotlin/okhttp3/Credentials.kt b/okhttp/src/jvmMain/kotlin/okhttp3/Credentials.kt
index 33f676b52028..5ae99cc8287d 100644
--- a/okhttp/src/jvmMain/kotlin/okhttp3/Credentials.kt
+++ b/okhttp/src/jvmMain/kotlin/okhttp3/Credentials.kt
@@ -16,7 +16,7 @@
 package okhttp3
 
 import java.nio.charset.Charset
-import java.nio.charset.StandardCharsets.ISO_8859_1
+import kotlin.text.Charsets.ISO_8859_1
 import okio.ByteString.Companion.encode
 
 /** Factory for HTTP authorization credentials. */
diff --git a/okhttp/src/jvmMain/kotlin/okhttp3/HttpUrl.kt b/okhttp/src/jvmMain/kotlin/okhttp3/HttpUrl.kt
index 498c02efad8e..2b8723e82b8c 100644
--- a/okhttp/src/jvmMain/kotlin/okhttp3/HttpUrl.kt
+++ b/okhttp/src/jvmMain/kotlin/okhttp3/HttpUrl.kt
@@ -21,8 +21,8 @@ import java.net.URI
 import java.net.URISyntaxException
 import java.net.URL
 import java.nio.charset.Charset
-import java.nio.charset.StandardCharsets.UTF_8
 import java.util.Collections
+import kotlin.text.Charsets.UTF_8
 import okhttp3.HttpUrl.Companion.toHttpUrl
 import okhttp3.HttpUrl.Companion.toHttpUrlOrNull
 import okhttp3.internal.canParseAsIpAddress
diff --git a/okhttp/src/jvmMain/kotlin/okhttp3/internal/-UtilJvm.kt b/okhttp/src/jvmMain/kotlin/okhttp3/internal/-UtilJvm.kt
index b591a517bec8..0149232843e2 100644
--- a/okhttp/src/jvmMain/kotlin/okhttp3/internal/-UtilJvm.kt
+++ b/okhttp/src/jvmMain/kotlin/okhttp3/internal/-UtilJvm.kt
@@ -22,16 +22,16 @@ import java.net.ServerSocket
 import java.net.Socket
 import java.net.SocketTimeoutException
 import java.nio.charset.Charset
-import java.nio.charset.StandardCharsets.UTF_16BE
-import java.nio.charset.StandardCharsets.UTF_16LE
-import java.nio.charset.StandardCharsets.UTF_8
 import java.util.Collections
 import java.util.Locale
 import java.util.TimeZone
 import java.util.concurrent.ThreadFactory
 import java.util.concurrent.TimeUnit
+import kotlin.text.Charsets.UTF_16BE
+import kotlin.text.Charsets.UTF_16LE
 import kotlin.text.Charsets.UTF_32BE
 import kotlin.text.Charsets.UTF_32LE
+import kotlin.text.Charsets.UTF_8
 import okhttp3.EventListener
 import okhttp3.Headers
 import okhttp3.Headers.Companion.headersOf
diff --git a/okhttp/src/jvmMain/kotlin/okhttp3/internal/platform/android/AndroidSocketAdapter.kt b/okhttp/src/jvmMain/kotlin/okhttp3/internal/platform/android/AndroidSocketAdapter.kt
index 666277335e2d..ce3a606cbd7b 100644
--- a/okhttp/src/jvmMain/kotlin/okhttp3/internal/platform/android/AndroidSocketAdapter.kt
+++ b/okhttp/src/jvmMain/kotlin/okhttp3/internal/platform/android/AndroidSocketAdapter.kt
@@ -17,7 +17,6 @@ package okhttp3.internal.platform.android
 
 import java.lang.reflect.InvocationTargetException
 import java.lang.reflect.Method
-import java.nio.charset.StandardCharsets
 import javax.net.ssl.SSLSocket
 import okhttp3.Protocol
 import okhttp3.internal.platform.AndroidPlatform
@@ -79,7 +78,7 @@ open class AndroidSocketAdapter(private val sslSocketClass: Class<in SSLSocket>)
 
     return try {
       val alpnResult = getAlpnSelectedProtocol.invoke(sslSocket) as ByteArray?
-      if (alpnResult != null) String(alpnResult, StandardCharsets.UTF_8) else null
+      if (alpnResult != null) String(alpnResult, Charsets.UTF_8) else null
     } catch (e: NullPointerException) {
       // https://github.com/square/okhttp/issues/5587
       when (e.message) {
diff --git a/okhttp/src/jvmMain/kotlin/okhttp3/internal/publicsuffix/PublicSuffixDatabase.kt b/okhttp/src/jvmMain/kotlin/okhttp3/internal/publicsuffix/PublicSuffixDatabase.kt
index 2c65c286deee..e3188e18fc9d 100644
--- a/okhttp/src/jvmMain/kotlin/okhttp3/internal/publicsuffix/PublicSuffixDatabase.kt
+++ b/okhttp/src/jvmMain/kotlin/okhttp3/internal/publicsuffix/PublicSuffixDatabase.kt
@@ -18,9 +18,9 @@ package okhttp3.internal.publicsuffix
 import java.io.IOException
 import java.io.InterruptedIOException
 import java.net.IDN
-import java.nio.charset.StandardCharsets.UTF_8
 import java.util.concurrent.CountDownLatch
 import java.util.concurrent.atomic.AtomicBoolean
+import kotlin.text.Charsets.UTF_8
 import okhttp3.internal.and
 import okhttp3.internal.platform.Platform
 import okio.GzipSource
diff --git a/okhttp/src/jvmTest/java/okhttp3/MediaTypeJvmTest.kt b/okhttp/src/jvmTest/java/okhttp3/MediaTypeJvmTest.kt
index fd7f8e9ad6b4..d2e87b88c521 100644
--- a/okhttp/src/jvmTest/java/okhttp3/MediaTypeJvmTest.kt
+++ b/okhttp/src/jvmTest/java/okhttp3/MediaTypeJvmTest.kt
@@ -15,7 +15,6 @@
  */
 package okhttp3
 
-import java.nio.charset.StandardCharsets
 import java.util.*
 import kotlin.test.assertEquals
 import kotlin.test.assertNull
@@ -39,17 +38,17 @@ class MediaTypeJvmTest: MediaTypeGetTest() {
   @Test fun testDefaultCharset() {
     val noCharset = parse("text/plain")
     assertEquals(
-      "UTF-8", noCharset.charset(StandardCharsets.UTF_8)!!.name()
+      "UTF-8", noCharset.charset(Charsets.UTF_8)!!.name()
     )
     assertEquals(
-      "US-ASCII", noCharset.charset(StandardCharsets.US_ASCII)!!.name()
+      "US-ASCII", noCharset.charset(Charsets.US_ASCII)!!.name()
     )
     val charset = parse("text/plain; charset=iso-8859-1")
     assertEquals(
-      "ISO-8859-1", charset.charset(StandardCharsets.UTF_8)!!.name()
+      "ISO-8859-1", charset.charset(Charsets.UTF_8)!!.name()
     )
     assertEquals(
-      "ISO-8859-1", charset.charset(StandardCharsets.US_ASCII)!!.name()
+      "ISO-8859-1", charset.charset(Charsets.US_ASCII)!!.name()
     )
   }
 
diff --git a/okhttp/src/jvmTest/java/okhttp3/URLConnectionTest.kt b/okhttp/src/jvmTest/java/okhttp3/URLConnectionTest.kt
index ef98abc02dc1..f7e3485f3c72 100644
--- a/okhttp/src/jvmTest/java/okhttp3/URLConnectionTest.kt
+++ b/okhttp/src/jvmTest/java/okhttp3/URLConnectionTest.kt
@@ -34,7 +34,6 @@ import java.net.SocketTimeoutException
 import java.net.URI
 import java.net.URLConnection
 import java.net.UnknownHostException
-import java.nio.charset.StandardCharsets
 import java.security.KeyStore
 import java.security.cert.CertificateException
 import java.security.cert.X509Certificate
@@ -2890,7 +2889,7 @@ class URLConnectionTest {
     } catch (expected: IllegalStateException) {
     }
     try {
-      sinkReference.get().write("ghi".toByteArray(StandardCharsets.UTF_8))
+      sinkReference.get().write("ghi".toByteArray(Charsets.UTF_8))
       sinkReference.get().emit()
       fail<Any>()
     } catch (expected: IllegalStateException) {
diff --git a/okhttp/src/jvmTest/java/okhttp3/internal/http2/Http2ConnectionTest.kt b/okhttp/src/jvmTest/java/okhttp3/internal/http2/Http2ConnectionTest.kt
index d97380beda0e..4f1593e15e16 100644
--- a/okhttp/src/jvmTest/java/okhttp3/internal/http2/Http2ConnectionTest.kt
+++ b/okhttp/src/jvmTest/java/okhttp3/internal/http2/Http2ConnectionTest.kt
@@ -18,10 +18,10 @@ package okhttp3.internal.http2
 import java.io.EOFException
 import java.io.IOException
 import java.io.InterruptedIOException
-import java.nio.charset.StandardCharsets.UTF_8
 import java.util.concurrent.CountDownLatch
 import java.util.concurrent.TimeUnit
 import java.util.concurrent.atomic.AtomicInteger
+import kotlin.text.Charsets.UTF_8
 import okhttp3.Headers.Companion.headersOf
 import okhttp3.TestUtil.headerEntries
 import okhttp3.TestUtil.repeat
diff --git a/okhttp/src/jvmTest/java/okhttp3/internal/http2/HttpOverHttp2Test.kt b/okhttp/src/jvmTest/java/okhttp3/internal/http2/HttpOverHttp2Test.kt
index 52291b2e8991..1b66da39b6b2 100644
--- a/okhttp/src/jvmTest/java/okhttp3/internal/http2/HttpOverHttp2Test.kt
+++ b/okhttp/src/jvmTest/java/okhttp3/internal/http2/HttpOverHttp2Test.kt
@@ -19,7 +19,6 @@ import java.io.File
 import java.io.IOException
 import java.net.HttpURLConnection
 import java.net.SocketTimeoutException
-import java.nio.charset.StandardCharsets
 import java.time.Duration
 import java.util.Arrays
 import java.util.concurrent.BlockingQueue
@@ -243,7 +242,7 @@ class HttpOverHttp2Test {
   @ParameterizedTest @ArgumentsSource(ProtocolParamProvider::class)
   fun noDefaultContentLengthOnStreamingPost(protocol: Protocol, mockWebServer: MockWebServer) {
     setUp(protocol, mockWebServer)
-    val postBytes = "FGHIJ".toByteArray(StandardCharsets.UTF_8)
+    val postBytes = "FGHIJ".toByteArray(Charsets.UTF_8)
     server.enqueue(MockResponse().setBody("ABCDE"))
     val call = client.newCall(
       Request.Builder()
@@ -268,7 +267,7 @@ class HttpOverHttp2Test {
   @ParameterizedTest @ArgumentsSource(ProtocolParamProvider::class)
   fun userSuppliedContentLengthHeader(protocol: Protocol, mockWebServer: MockWebServer) {
     setUp(protocol, mockWebServer)
-    val postBytes = "FGHIJ".toByteArray(StandardCharsets.UTF_8)
+    val postBytes = "FGHIJ".toByteArray(Charsets.UTF_8)
     server.enqueue(MockResponse().setBody("ABCDE"))
     val call = client.newCall(
       Request.Builder()
@@ -299,7 +298,7 @@ class HttpOverHttp2Test {
     protocol: Protocol, mockWebServer: MockWebServer
   ) {
     setUp(protocol, mockWebServer)
-    val postBytes = "FGHIJ".toByteArray(StandardCharsets.UTF_8)
+    val postBytes = "FGHIJ".toByteArray(Charsets.UTF_8)
     server.enqueue(MockResponse().setBody("ABCDE"))
     val call = client.newCall(
       Request.Builder()
diff --git a/okhttp/src/jvmTest/java/okhttp3/internal/tls/HostnameVerifierTest.kt b/okhttp/src/jvmTest/java/okhttp3/internal/tls/HostnameVerifierTest.kt
index 0fc71db7953c..cd2f1adf5433 100644
--- a/okhttp/src/jvmTest/java/okhttp3/internal/tls/HostnameVerifierTest.kt
+++ b/okhttp/src/jvmTest/java/okhttp3/internal/tls/HostnameVerifierTest.kt
@@ -17,12 +17,12 @@
 package okhttp3.internal.tls
 
 import java.io.ByteArrayInputStream
-import java.nio.charset.StandardCharsets.UTF_8
 import java.security.cert.CertificateFactory
 import java.security.cert.X509Certificate
 import java.util.stream.Stream
 import javax.net.ssl.SSLSession
 import javax.security.auth.x500.X500Principal
+import kotlin.text.Charsets.UTF_8
 import okhttp3.FakeSSLSession
 import okhttp3.OkHttpClient
 import okhttp3.internal.canParseAsIpAddress