diff --git a/RELEASENOTES.md b/RELEASENOTES.md
index 61a4a6900c..41cf46d3b7 100644
--- a/RELEASENOTES.md
+++ b/RELEASENOTES.md
@@ -5,6 +5,9 @@
 *   Data sources:
     *   Add support for `android.resource` URI scheme in `RawResourceDataSource`
         ([#7866](https://github.com/google/ExoPlayer/issues/7866)).
+*   Core library:
+    *   Suppress Guava-related ProGuard/R8 warnings
+        ([#7904](https://github.com/google/ExoPlayer/issues/7904)).
 
 ### 2.12.0 (2020-09-11) ###
 
diff --git a/library/common/proguard-rules.txt b/library/common/proguard-rules.txt
index c83dbaee2d..18e5264c20 100644
--- a/library/common/proguard-rules.txt
+++ b/library/common/proguard-rules.txt
@@ -4,3 +4,6 @@
 -dontwarn org.checkerframework.**
 -dontwarn kotlin.annotations.jvm.**
 -dontwarn javax.annotation.**
+
+# From https://github.com/google/guava/wiki/UsingProGuardWithGuava
+-dontwarn java.lang.ClassValue
diff --git a/library/core/proguard-rules.txt b/library/core/proguard-rules.txt
index 64c8cb2435..35a7fdfeaa 100644
--- a/library/core/proguard-rules.txt
+++ b/library/core/proguard-rules.txt
@@ -71,8 +71,3 @@
 -keepclasseswithmembers class com.google.android.exoplayer2.source.smoothstreaming.SsMediaSource$Factory {
   <init>(com.google.android.exoplayer2.upstream.DataSource$Factory);
 }
-
-# Don't warn about checkerframework and Kotlin annotations
--dontwarn org.checkerframework.**
--dontwarn kotlin.annotations.jvm.**
--dontwarn javax.annotation.**