diff --git a/index.bs b/index.bs
index 252ec840..71bd6594 100644
--- a/index.bs
+++ b/index.bs
@@ -7524,8 +7524,9 @@ TODO: Extend this to scripts in other kinds of realms.
 A [=BiDi session=] has a <dfn>preload script map</dfn> which is a [=/map=] in
 which the keys are [[!RFC9562|UUID]]s, and the values are [=structs=] with an <a
 for=struct>item</a> named <code>function declaration</code>, which is a string,
-<code>arguments</code>, <code>contexts</code>, which is a list or null, and an item named <code>sandbox</code> which is a string
-or null.
+<code>arguments</code>, <code>contexts</code>, which is a list or null,
+an item named <code>sandbox</code>, which is a string or null,
+and an item named <code>applyToOpeningContexts</code>, which is a boolean.
 
 Note: If executing a [=preload script=] fails, either due to a syntax error, or
 a runtime exception, an [[ECMAScript]] exception is reported in the realm in
@@ -7546,9 +7547,19 @@ To <dfn export>run WebDriver BiDi preload scripts</dfn> given |environment setti
 
     1. If |preload script|'s <code>contexts</code> is not null:
 
-       1. Let |navigable id| be |navigable|’s [=navigable/top-level traversable=]'s id.
+       1. Let |is script run allowed| be false.
 
-       1. If |preload script|'s <code>contexts</code> does not [=list/contains|contain=] |navigable id|, continue.
+       1. While |navigable| is not null:
+
+          1. Let |navigable id| be |navigable|’s [=navigable/top-level traversable=]'s id.
+
+          1. If |preload script|'s <code>contexts</code> [=list/contains=] |navigable id|,
+            set |is script run allowed| to true and break.
+
+          1. If |preload script|'s <code>applyToOpeningContexts</code> is true,
+            set |navigable| to |navigable|'s [=original opener=]. Otherwise, break.
+
+        1. If |is script run allowed| is false, continue;
 
     1. If |preload script|'s <code>sandbox</code> is not null, let |realm| be [=get
        or create a sandbox realm=] with |preload script|'s <code>sandbox</code> and
@@ -9479,6 +9490,7 @@ script=].
         functionDeclaration: text,
         ? arguments: [*script.ChannelValue],
         ? contexts: [+browsingContext.BrowsingContext],
+        ? applyToOpeningContexts: bool .default false,
         ? sandbox: text
       }
       </pre>
@@ -9519,6 +9531,9 @@ The [=remote end steps=] given |session| and |command parameters| are:
 1. Let |sandbox| be the value of the "<code>sandbox</code>" field in |command
    parameters|, if present, or null otherwise.
 
+1. Let |applyToOpeningContexts| be true if |command parameters|["<code>applyToOpeningContexts</code>"]
+  is true, and false otherwise.
+
 1. Let |script| be the string representation of a [[!RFC9562|UUID]].
 
 1. Let |preload script map| be |session|'s [=preload script map=].
@@ -9526,7 +9541,8 @@ The [=remote end steps=] given |session| and |command parameters| are:
 1. Set |preload script map|[|script|] to a struct with <code>function
    declaration</code> |function declaration|, <code>arguments</code>
    |arguments|, <code>contexts</code>
-   |navigables|, and <code>sandbox</code> |sandbox|.
+   |navigables|, <code>sandbox</code> |sandbox|, and
+   <code>applyToOpeningContexts</code> |applyToOpeningContexts|.
 
 1. Return a new [=/map=] matching the <code>script.AddPreloadScriptResult</code> with the
    <code>script</code> field set to |script|.