diff --git a/.circleci/config.yml b/.circleci/config.yml
index e1aeae9cee..1841d762aa 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -3,28 +3,28 @@ version: 2.1
 parameters:
   xcode_version:
     type: string
-    default: "13.0.0"
+    default: "13.2.1"
   ios_current_version:
     type: string
-    default: "15.0"
+    default: "15.2"
   ios_previous_version:
     type: string
     default: "14.5"
   ios_sdk:
     type: string
-    default: "iphonesimulator15.0"
+    default: "iphonesimulator15.2"
   macos_version: # The user-facing version string for macOS builds
     type: string
-    default: "11.5.2"
+    default: "11.6.2"
   macos_sdk: # The full SDK string to use for macOS builds
     type: string
-    default: "macosx11.3"
+    default: "macosx12.1"
   tvos_version: # The user-facing version string of tvOS builds
     type: string
-    default: "15.0"
+    default: "15.2"
   tvos_sdk:
     type: string
-    default: "appletvsimulator15.0"
+    default: "appletvsimulator15.2"
 
 commands:
   integration_test_setup:
diff --git a/Sources/ApolloCodegenLib/Frontend/JavaScriptBridge.swift b/Sources/ApolloCodegenLib/Frontend/JavaScriptBridge.swift
index 395436b220..35a7c8ae93 100644
--- a/Sources/ApolloCodegenLib/Frontend/JavaScriptBridge.swift
+++ b/Sources/ApolloCodegenLib/Frontend/JavaScriptBridge.swift
@@ -4,14 +4,15 @@ import JavaScriptCore
 // and can be safely force unwrapped. (Even when an exception is thrown they would still return
 // a `JSValue` representing a JavaScript `undefined` value.)
 
-/// An errror thrown during JavaScript execution.
+/// An error thrown during JavaScript execution.
 /// See https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error
-public class JavaScriptError: JavaScriptObject, Error {
-  lazy var name: String? = self["name"]
-  
-  lazy var message: String? = self["message"]
-  
-  lazy var stack: String? = self["stack"]
+public class JavaScriptError: JavaScriptObject, Error, @unchecked Sendable {
+  // These properties were changed to read-only when `@unchecked Sendable` was added for
+  // Xcode 13.3. If you make them publicly writable or alter their values within the class
+  // you will need to do so with thread-safety in mind.
+  var name: String? { self["name"] }
+  var message: String? { self["message"] }
+  var stack: String? { self["stack"] }
 }
 
 extension JavaScriptError: CustomStringConvertible {