diff --git a/webextensions/api/runtime.json b/webextensions/api/runtime.json
index 87952997ec03b1..ce82e1d56be725 100644
--- a/webextensions/api/runtime.json
+++ b/webextensions/api/runtime.json
@@ -360,7 +360,8 @@
             "__compat": {
               "support": {
                 "chrome": {
-                  "version_added": "≤58"
+                  "version_added": "28",
+                  "notes": "This attribute is deprecated and is being removed from Google Chrome, following removal of Google Native Client."
                 },
                 "edge": "mirror",
                 "firefox": {
@@ -381,7 +382,8 @@
             "mdn_url": "https://developer.mozilla.org/docs/Mozilla/Add-ons/WebExtensions/API/runtime/PlatformNaclArch",
             "support": {
               "chrome": {
-                "version_added": "≤58"
+                "version_added": "28",
+                "notes": "This enum is deprecated and is being removed from Google Chrome, following removal of Google Native Client."
               },
               "edge": "mirror",
               "firefox": {