diff --git a/README.md b/README.md
index b674b6fcd..920bbdd99 100644
--- a/README.md
+++ b/README.md
@@ -99,10 +99,10 @@ Releases
 
 Our [change log][changelog] has release history.
 
-The latest release is available on [Maven Central](https://search.maven.org/artifact/com.squareup.okhttp3/okhttp/4.9.3/jar).
+The latest release is available on [Maven Central](https://search.maven.org/artifact/com.squareup.okhttp3/okhttp/4.10.0/jar).
 
 ```kotlin
-implementation("com.squareup.okhttp3:okhttp:4.9.3")
+implementation("com.squareup.okhttp3:okhttp:4.10.0")
 ```
 
 Snapshot builds are [available][snap]. [R8 and ProGuard][r8_proguard] rules are available.
@@ -112,7 +112,7 @@ Also, we have a [bill of materials (BOM)][bom] available to help you keep OkHttp
 ```kotlin
     dependencies {
        // define a BOM and its version
-       implementation(platform("com.squareup.okhttp3:okhttp-bom:4.9.3"))
+       implementation(platform("com.squareup.okhttp3:okhttp-bom:4.10.0"))
 
        // define any required OkHttp artifacts without version
        implementation("com.squareup.okhttp3:okhttp")
@@ -125,10 +125,10 @@ MockWebServer
 
 OkHttp includes a library for testing HTTP, HTTPS, and HTTP/2 clients.
 
-The latest release is available on [Maven Central](https://search.maven.org/artifact/com.squareup.okhttp3/mockwebserver/4.9.3/jar).
+The latest release is available on [Maven Central](https://search.maven.org/artifact/com.squareup.okhttp3/mockwebserver/4.10.0/jar).
 
 ```kotlin
-testImplementation("com.squareup.okhttp3:mockwebserver:4.9.3")
+testImplementation("com.squareup.okhttp3:mockwebserver:4.10.0")
 ```
 
 GraalVM Native Image
diff --git a/docs/changelogs/changelog_4x.md b/docs/changelogs/changelog_4x.md
index 048843c3b..ab893865f 100644
--- a/docs/changelogs/changelog_4x.md
+++ b/docs/changelogs/changelog_4x.md
@@ -1,6 +1,16 @@
 OkHttp 4.x Change Log
 =====================
 
+## Version 4.10.0
+
+_2021-06-12_
+
+ *  Upgrade: [Kotlin 1.6.20][kotlin_1_6_20].
+ *  Upgrade: [Okio 3.0.0][okio_3_0_0].
+ *  Fix: Recover gracefully when Android's `NativeCrypto` crashes with `"ssl == null"`. This occurs
+    when OkHttp retrieves ALPN state on a closed connection.
+
+
 ## Version 4.9.3
 
 _2021-11-21_
@@ -528,11 +538,13 @@ _2019-06-03_
  [jetty_8_252]: https://webtide.com/jetty-alpn-java-8u252/
  [kotlin_1_3_71]: https://github.com/JetBrains/kotlin/releases/tag/v1.3.71
  [kotlin_1_4_10]: https://github.com/JetBrains/kotlin/releases/tag/v1.4.10
+ [kotlin_1_6_20]: https://github.com/JetBrains/kotlin/releases/tag/v1.6.20
  [legacy_interceptor]: https://gist.github.com/swankjesse/80135f4e03629527e723ab3bcf64be0b
  [okhttp4_blog_post]: https://cashapp.github.io/2019-06-26/okhttp-4-goes-kotlin
  [okio.FileSystem]: https://square.github.io/okio/file_system/
  [okio_2_6_0]: https://square.github.io/okio/changelog/#version-260
  [okio_2_7_0]: https://square.github.io/okio/changelog/#version-270
+ [okio_3_0_0]: https://square.github.io/okio/changelog/#version-300
  [public_suffix]: https://publicsuffix.org/
  [rfc_2045]: https://tools.ietf.org/html/rfc2045
  [rfc_7231_647]: https://tools.ietf.org/html/rfc7231#section-6.4.7
diff --git a/mockwebserver-junit4/README.md b/mockwebserver-junit4/README.md
index 0b98059a3..370ee729d 100644
--- a/mockwebserver-junit4/README.md
+++ b/mockwebserver-junit4/README.md
@@ -6,7 +6,7 @@ This module integrates mockwebserver3.MockWebServer with JUnit 4.
 To use, first add this library as a test dependency:
 
 ```
-testImplementation("com.squareup.okhttp3:mockwebserver3-junit4:4.9.3")
+testImplementation("com.squareup.okhttp3:mockwebserver3-junit4:4.10.0")
 ```
 
 Then in tests annotated `@org.junit.Test`, you may declare a field with the `@Rule` annotation:
diff --git a/mockwebserver-junit5/README.md b/mockwebserver-junit5/README.md
index e1478f869..b540ac65d 100644
--- a/mockwebserver-junit5/README.md
+++ b/mockwebserver-junit5/README.md
@@ -6,7 +6,7 @@ This module integrates mockwebserver3.MockWebServer with JUnit 5.
 To use, first add this library as a test dependency:
 
 ```
-testRuntimeOnly("com.squareup.okhttp3:mockwebserver3-junit5:4.9.3")
+testRuntimeOnly("com.squareup.okhttp3:mockwebserver3-junit5:4.10.0")
 ```
 
 Then in tests annotated `@org.junit.jupiter.api.Test`, you may add a [MockWebServer] as a test
diff --git a/mockwebserver/README.md b/mockwebserver/README.md
index 70ec778c8..8ef4019be 100644
--- a/mockwebserver/README.md
+++ b/mockwebserver/README.md
@@ -142,7 +142,7 @@ server.setDispatcher(dispatcher);
 ### Download
 
 ```kotlin
-testImplementation("com.squareup.okhttp3:mockwebserver:4.9.3")
+testImplementation("com.squareup.okhttp3:mockwebserver:4.10.0")
 ```
 
 ### License
diff --git a/okhttp-android/README.md b/okhttp-android/README.md
index 1dbcbe115..e0c12f71c 100644
--- a/okhttp-android/README.md
+++ b/okhttp-android/README.md
@@ -9,5 +9,5 @@ Download
 --------
 
 ```kotlin
-implementation("com.squareup.okhttp3:okhttp-android:4.9.3")
+implementation("com.squareup.okhttp3:okhttp-android:4.10.0")
 ```
diff --git a/okhttp-brotli/README.md b/okhttp-brotli/README.md
index a1d3221bc..9e48e31a1 100644
--- a/okhttp-brotli/README.md
+++ b/okhttp-brotli/README.md
@@ -14,7 +14,7 @@ OkHttpClient client = new OkHttpClient.Builder()
 ```
 
 ```kotlin
-implementation("com.squareup.okhttp3:okhttp-brotli:4.9.3")
+implementation("com.squareup.okhttp3:okhttp-brotli:4.10.0")
 ```
 
  [1]: https://github.com/google/brotli
diff --git a/okhttp-dnsoverhttps/README.md b/okhttp-dnsoverhttps/README.md
index fb4e800db..9da13f397 100644
--- a/okhttp-dnsoverhttps/README.md
+++ b/okhttp-dnsoverhttps/README.md
@@ -6,7 +6,7 @@ This module is an implementation of [DNS over HTTPS][1] using OkHttp.
 ### Download
 
 ```kotlin
-testImplementation("com.squareup.okhttp3:okhttp-dnsoverhttps:4.9.3")
+testImplementation("com.squareup.okhttp3:okhttp-dnsoverhttps:4.10.0")
 ```
 
 ### Usage
diff --git a/okhttp-logging-interceptor/README.md b/okhttp-logging-interceptor/README.md
index 8822e8d6c..3f9503880 100644
--- a/okhttp-logging-interceptor/README.md
+++ b/okhttp-logging-interceptor/README.md
@@ -37,7 +37,7 @@ Download
 --------
 
 ```kotlin
-implementation("com.squareup.okhttp3:logging-interceptor:4.9.3")
+implementation("com.squareup.okhttp3:logging-interceptor:4.10.0")
 ```
 
 
diff --git a/okhttp-sse/README.md b/okhttp-sse/README.md
index b22cd5a2b..1aee5a533 100644
--- a/okhttp-sse/README.md
+++ b/okhttp-sse/README.md
@@ -7,5 +7,5 @@ API is not considered stable and may change at any time.
 ### Download
 
 ```kotlin
-testImplementation("com.squareup.okhttp3:okhttp-sse:4.9.3")
+testImplementation("com.squareup.okhttp3:okhttp-sse:4.10.0")
 ```
diff --git a/okhttp-tls/README.md b/okhttp-tls/README.md
index fd8ff2d80..efa22dab9 100644
--- a/okhttp-tls/README.md
+++ b/okhttp-tls/README.md
@@ -227,7 +227,7 @@ Download
 --------
 
 ```kotlin
-implementation("com.squareup.okhttp3:okhttp-tls:4.9.3")
+implementation("com.squareup.okhttp3:okhttp-tls:4.10.0")
 ```
 
  [held_certificate]: https://square.github.io/okhttp/4.x/okhttp-tls/okhttp3.tls/-held-certificate/
diff --git a/okhttp-urlconnection/README.md b/okhttp-urlconnection/README.md
index 7aaaf6763..a8cb2e5b5 100644
--- a/okhttp-urlconnection/README.md
+++ b/okhttp-urlconnection/README.md
@@ -6,5 +6,5 @@ This module integrates OkHttp with `Authenticator` and `CookieHandler` from `jav
 ### Download
 
 ```kotlin
-testImplementation("com.squareup.okhttp3:okhttp-urlconnection:4.9.3")
+testImplementation("com.squareup.okhttp3:okhttp-urlconnection:4.10.0")
 ```