diff --git a/CHANGELOG.md b/CHANGELOG.md
index d34749a31..ca66d9f2d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,17 @@ Change Log
 
 See [4.x Change log](https://square.github.io/okhttp/changelogs/changelog_4x/) for the stable version changelogs.
 
+## Version 5.2.1
+
+_2025-10-09_
+
+ *  Fix: Don't crash when calling `Socket.shutdownOutput()` or `shutdownInput()` on an `SSLSocket`
+    on Android API 21 through 23. This method throws an `UnsupportedOperationException`, so we now
+    catch that and close the underlying stream instead.
+
+ *  Upgrade: [Okio 3.16.1][okio_3_16_1].
+
+
 ## Version 5.2.0
 
 _2025-10-07_
diff --git a/README.md b/README.md
index 049c674ad..e9fc09959 100644
--- a/README.md
+++ b/README.md
@@ -123,10 +123,10 @@ 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/5.2.0/jar).
+The latest release is available on [Maven Central](https://search.maven.org/artifact/com.squareup.okhttp3/okhttp/5.2.1/jar).
 
 ```kotlin
-implementation("com.squareup.okhttp3:okhttp:5.2.0")
+implementation("com.squareup.okhttp3:okhttp:5.2.1")
 ```
 
 Snapshot builds are [available][snap]. [R8 and ProGuard][r8_proguard] rules are available.
@@ -136,7 +136,7 @@ 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:5.2.0"))
+       implementation(platform("com.squareup.okhttp3:okhttp-bom:5.2.1"))
 
        // define any required OkHttp artifacts without version
        implementation("com.squareup.okhttp3:okhttp")
@@ -191,10 +191,10 @@ 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/5.2.0/jar).
+The latest release is available on [Maven Central](https://search.maven.org/artifact/com.squareup.okhttp3/mockwebserver/5.2.1/jar).
 
 ```kotlin
-testImplementation("com.squareup.okhttp3:mockwebserver3:5.2.0")
+testImplementation("com.squareup.okhttp3:mockwebserver3:5.2.1")
 ```
 
 MockWebServer is used for firstly for internal testing, and for basic testing of apps using OkHttp client.
diff --git a/mockwebserver-junit4/README.md b/mockwebserver-junit4/README.md
index dc1e893fc..e46546f0b 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-junit4:5.2.0")
+testImplementation("com.squareup.okhttp3:mockwebserver3-junit4:5.2.1")
 ```
 
 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 4d204a67d..12f26375e 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:
 
 ```
-testImplementation("com.squareup.okhttp3:mockwebserver3-junit5:5.2.0")
+testImplementation("com.squareup.okhttp3:mockwebserver3-junit5:5.2.1")
 ```
 
 Annotate fields in test classes with `@StartStop`. The server will be started and shut down
diff --git a/mockwebserver/README.md b/mockwebserver/README.md
index 3c8ca911c..86e362781 100644
--- a/mockwebserver/README.md
+++ b/mockwebserver/README.md
@@ -270,7 +270,7 @@ server.dispatcher = dispatcher
 ### Download
 
 ```kotlin
-testImplementation("com.squareup.okhttp3:mockwebserver3:5.2.0")
+testImplementation("com.squareup.okhttp3:mockwebserver3:5.2.1")
 ```
 
 ### License
diff --git a/okhttp-brotli/README.md b/okhttp-brotli/README.md
index afba59764..7d8dd9862 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:5.2.0")
+implementation("com.squareup.okhttp3:okhttp-brotli:5.2.1")
 ```
 
  [1]: https://github.com/google/brotli
diff --git a/okhttp-dnsoverhttps/README.md b/okhttp-dnsoverhttps/README.md
index 9f34b71d9..44b8428ee 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:5.2.0")
+testImplementation("com.squareup.okhttp3:okhttp-dnsoverhttps:5.2.1")
 ```
 
 ### Usage
diff --git a/okhttp-java-net-cookiejar/README.md b/okhttp-java-net-cookiejar/README.md
index d541b49e1..6f8912c0f 100644
--- a/okhttp-java-net-cookiejar/README.md
+++ b/okhttp-java-net-cookiejar/README.md
@@ -7,5 +7,5 @@ This used to be part of `okhttp-urlconnection`
 ### Download
 
 ```kotlin
-testImplementation("com.squareup.okhttp3:okhttp-java-net-cookiehandler:5.2.0")
+testImplementation("com.squareup.okhttp3:okhttp-java-net-cookiehandler:5.2.1")
 ```
diff --git a/okhttp-logging-interceptor/README.md b/okhttp-logging-interceptor/README.md
index 9d62f49e2..0fc500ca4 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:5.2.0")
+implementation("com.squareup.okhttp3:logging-interceptor:5.2.1")
 ```
 
 
diff --git a/okhttp-sse/README.md b/okhttp-sse/README.md
index d4c0192df..832aca228 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:5.2.0")
+testImplementation("com.squareup.okhttp3:okhttp-sse:5.2.1")
 ```
diff --git a/okhttp-tls/README.md b/okhttp-tls/README.md
index 6c702ed00..c92486ffc 100644
--- a/okhttp-tls/README.md
+++ b/okhttp-tls/README.md
@@ -225,7 +225,7 @@ Download
 --------
 
 ```kotlin
-implementation("com.squareup.okhttp3:okhttp-tls:5.2.0")
+implementation("com.squareup.okhttp3:okhttp-tls:5.2.1")
 ```
 
  [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 db5e158bd..4a1ccb534 100644
--- a/okhttp-urlconnection/README.md
+++ b/okhttp-urlconnection/README.md
@@ -8,5 +8,5 @@ This module is obsolete; prefer `okhttp-java-net-cookiejar`.
 ### Download
 
 ```kotlin
-testImplementation("com.squareup.okhttp3:okhttp-urlconnection:5.2.0")
+testImplementation("com.squareup.okhttp3:okhttp-urlconnection:5.2.1")
 ```
diff --git a/okhttp-zstd/README.md b/okhttp-zstd/README.md
index c0d5c767c..a453511f7 100644
--- a/okhttp-zstd/README.md
+++ b/okhttp-zstd/README.md
@@ -14,7 +14,7 @@ OkHttpClient client = new OkHttpClient.Builder()
 ```
 
 ```kotlin
-implementation("com.squareup.okhttp3:okhttp-zstd:5.2.0")
+implementation("com.squareup.okhttp3:okhttp-zstd:5.2.1")
 ```
 
  [1]: https://github.com/facebook/zstd