diff --git a/api/DeviceMotionEventAcceleration.json b/api/DeviceMotionEventAcceleration.json
index e798c84c9c4534..261ddd31f1371d 100644
--- a/api/DeviceMotionEventAcceleration.json
+++ b/api/DeviceMotionEventAcceleration.json
@@ -16,7 +16,8 @@
             "version_added": "12"
           },
           "firefox": {
-            "version_added": "6"
+            "version_added": "6",
+            "notes": "The `DeviceMotionEventAcceleration` interface is supported, but not exposed on the `Window` scope."
           },
           "firefox_android": "mirror",
           "ie": {
@@ -29,7 +30,8 @@
             "version_added": false
           },
           "safari_ios": {
-            "version_added": "4.2"
+            "version_added": "4.2",
+            "notes": "The `DeviceMotionEventAcceleration` interface is supported, but not exposed on the `Window` scope."
           },
           "samsunginternet_android": "mirror",
           "webview_android": "mirror",