diff --git a/index.bs b/index.bs
index 21845cc4..dd94c3b7 100644
--- a/index.bs
+++ b/index.bs
@@ -8236,8 +8236,15 @@ IDL [=promise type=] values are represented by ECMAScript [=PromiseCapability=]
steps:
1. Let |onFulfilledSteps| be the following steps given argument |V|:
- 1. Let |value| be the result of [=converted to an IDL value|converting=] |V| to an IDL
- value of type |T|.
+ 1. Try running the following step:
+ 1. Let |value| be the result of [=converted to an IDL value|converting=] |V| to an IDL
+ value of type |T|.
+
+ And then, if an exception |exception| was thrown:
+
+ 1. If there are steps that are required to be run if the promise was rejected, let
+ |result| be the result of performing those steps, given |exception|.
+ 1. [=ECMAScript/throw=] |exception|.
1. If there are no steps that are required to be run if the promise was fulfilled, then
return undefined.
1. Let |result| be the result of performing any steps that were required to be run if