diff --git a/atoms.proto b/atoms.proto
index e7cce06..847c298 100644
--- a/atoms.proto
+++ b/atoms.proto
@@ -321,6 +321,9 @@
             218  [(log_from_module) = "permissioncontroller"];
         ExclusionRectStateChanged exclusion_rect_state_changed = 223;
         BackGesture back_gesture_reported_reported = 224;
+
+        AppCompatibilityChangeReported app_compatibility_change_reported =
+            228 [(allow_from_any_uid) = true];
     }
 
     // Pulled events will start at field 10000.
@@ -6818,3 +6821,39 @@
     }
     optional Category category = 6;
 }
+
+/**
+ * Logs when a compatibility change is affecting an app.
+ *
+ * Logged from:
+ *   frameworks/base/core/java/android/app/AppCompatCallbacks.java and
+ *   frameworks/base/services/core/java/com/android/server/compat/PlatformCompat.java
+ */
+message AppCompatibilityChangeReported {
+    // The UID of the app being affected by the compatibilty change.
+    optional int32 uid = 1 [(is_uid) = true];
+
+    // The ID of the change affecting the app.
+    optional int64 change_id = 2;
+
+    enum State {
+        UNKNOWN_STATE = 0;
+        ENABLED = 1;
+        DISABLED = 2;
+        LOGGED = 3;
+    }
+
+    // The state of the change - if logged from gating whether it was enabled or disabled, or just
+    // logged otherwise.
+    optional State state = 3;
+
+    enum Source {
+        UNKNOWN_SOURCE = 0;
+        APP_PROCESS = 1;
+        SYSTEM_SERVER = 2;
+    }
+
+    // Where it was logged from.
+    optional Source source = 4;
+
+}