diff --git a/RELEASENOTES.md b/RELEASENOTES.md
index 3c792b1bee..fdd8d2c5ea 100644
--- a/RELEASENOTES.md
+++ b/RELEASENOTES.md
@@ -59,7 +59,9 @@
   ([#6335](https://github.com/google/ExoPlayer/issues/6335)).
 * Add `HttpDataSource.getResponseCode` to provide the status code associated
   with the most recent HTTP response.
-* Upgrade LibRtmp-Client-for-Android to fix RTMP playback issues
+* OkHttp extension: Upgrade OkHttp to fix HTTP2 socket timeout issue
+  ([#4078](https://github.com/google/ExoPlayer/issues/4078)).
+* RTMP extension: Upgrade LibRtmp-Client-for-Android to fix RTMP playback issues
   ([#4200](https://github.com/google/ExoPlayer/issues/4200),
   [#4249](https://github.com/google/ExoPlayer/issues/4249),
   [#4319](https://github.com/google/ExoPlayer/issues/4319),
diff --git a/extensions/okhttp/build.gradle b/extensions/okhttp/build.gradle
index 7f638e3c23..3af38397a8 100644
--- a/extensions/okhttp/build.gradle
+++ b/extensions/okhttp/build.gradle
@@ -37,7 +37,11 @@ dependencies {
     compileOnly 'org.checkerframework:checker-qual:' + checkerframeworkVersion
     testImplementation project(modulePrefix + 'testutils')
     testImplementation 'org.robolectric:robolectric:' + robolectricVersion
-    api 'com.squareup.okhttp3:okhttp:3.12.1'
+    // Do not update to 3.13.X or later until minSdkVersion is increased to 21:
+    // https://cashapp.github.io/2019-02-05/okhttp-3-13-requires-android-5
+    // Since OkHttp is distributed as a jar rather than an aar, Gradle wont stop
+    // us from making this mistake!
+    api 'com.squareup.okhttp3:okhttp:3.12.5'
 }
 
 ext {