diff --git a/RELEASENOTES.md b/RELEASENOTES.md
index a8929bc156..a6df395d01 100644
--- a/RELEASENOTES.md
+++ b/RELEASENOTES.md
@@ -50,6 +50,8 @@
 * DRM:
   * Allow multiple listeners for `DefaultDrmSessionManager`.
   * Pass `DrmSessionManager` to `ExoPlayerFactory` instead of `RendererFactory`.
+  * Change minimum API requirement for CBC and pattern encryption from 24 to 25
+    ([#4022][https://github.com/google/ExoPlayer/issues/4022]).
 * Removed default renderer time offset of 60000000 from internal player. The
   actual renderer timestamp offset can be obtained by listening to
   `BaseRenderer.onStreamChanged`.
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/drm/DefaultDrmSessionManager.java b/library/core/src/main/java/com/google/android/exoplayer2/drm/DefaultDrmSessionManager.java
index 42e0e205a7..66c9e5cde7 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/drm/DefaultDrmSessionManager.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/drm/DefaultDrmSessionManager.java
@@ -491,8 +491,9 @@ public class DefaultDrmSessionManager<T extends ExoMediaCrypto> implements DrmSe
       return true;
     } else if (C.CENC_TYPE_cbc1.equals(schemeType) || C.CENC_TYPE_cbcs.equals(schemeType)
         || C.CENC_TYPE_cens.equals(schemeType)) {
-      // AES-CBC and pattern encryption are supported on API 24 onwards.
-      return Util.SDK_INT >= 24;
+      // API support for AES-CBC and pattern encryption was added in API 24. However, the
+      // implementation was not stable until API 25.
+      return Util.SDK_INT >= 25;
     }
     // Unknown schemes, assume one of them is supported.
     return true;