diff --git a/packages/playwright-core/browsers.json b/packages/playwright-core/browsers.json
index 94d8286f2622a..ee74af0d42081 100644
--- a/packages/playwright-core/browsers.json
+++ b/packages/playwright-core/browsers.json
@@ -24,7 +24,7 @@
     },
     {
       "name": "webkit",
-      "revision": "2365",
+      "revision": "2366",
       "installByDefault": true,
       "revisionOverrides": {
         "mac14": "2251",
diff --git a/packages/playwright-core/src/server/webkit/protocol.d.ts b/packages/playwright-core/src/server/webkit/protocol.d.ts
index 0352aa0671a49..15be64e3a562a 100644
--- a/packages/playwright-core/src/server/webkit/protocol.d.ts
+++ b/packages/playwright-core/src/server/webkit/protocol.d.ts
@@ -586,7 +586,7 @@ export namespace Protocol {
        */
       groupings?: Grouping[];
       /**
-       * <code>true</code> if this style is for a rule implicitly wrapping properties declared inside of CSSGrouping.
+       * <code>true</code> if this is a nested declarations rule holding declarations interleaved with other rules inside a style rule or nested grouping rule. Such a rule has no selector of its own, it matches whatever its nesting parent style rule matches.
        */
       isImplicitlyNested?: boolean;
     }