diff --git a/api/CanvasRenderingContext2D.json b/api/CanvasRenderingContext2D.json
index a4bf0c58f479dd..2beb0e51df1ece 100644
--- a/api/CanvasRenderingContext2D.json
+++ b/api/CanvasRenderingContext2D.json
@@ -1240,7 +1240,9 @@
               "version_added": "≤12.1"
             },
             "safari": {
-              "version_added": "4"
+              "version_added": "4",
+              "partial_implementation": true,
+              "notes": "The `font-weight` can be set, but is not reflected back (see [bug 288486](https://webkit.org/b/288486))."
             },
             "safari_ios": "mirror",
             "samsunginternet_android": "mirror",
diff --git a/api/OffscreenCanvasRenderingContext2D.json b/api/OffscreenCanvasRenderingContext2D.json
index 7823301757adf9..73069164c89e2a 100644
--- a/api/OffscreenCanvasRenderingContext2D.json
+++ b/api/OffscreenCanvasRenderingContext2D.json
@@ -898,7 +898,9 @@
             "opera": "mirror",
             "opera_android": "mirror",
             "safari": {
-              "version_added": "16.4"
+              "version_added": "16.4",
+              "partial_implementation": true,
+              "notes": "The `font-weight` can be set, but is not reflected back (see [bug 288486](https://webkit.org/b/288486))."
             },
             "safari_ios": "mirror",
             "samsunginternet_android": "mirror",