diff --git a/Package.resolved b/Package.resolved
index 9b34730..6395398 100644
--- a/Package.resolved
+++ b/Package.resolved
@@ -1,13 +1,13 @@
 {
-  "originHash" : "ee65e45727e23405f73ea91a23159b5f8aa39b46eecc8209fdf25716491f41c1",
+  "originHash" : "4664fc67474c8651eb974fc9c02bf4ae3b4be2c93876069688a3793a21f9ccc9",
   "pins" : [
     {
       "identity" : "appupdater",
       "kind" : "remoteSourceControl",
       "location" : "https://github.com/mxcl/AppUpdater.git",
       "state" : {
-        "revision" : "4826e7205ed0159347de84b19960f4ba0e535504",
-        "version" : "4.1.2"
+        "revision" : "a2b89896ebc6c5194b67d38a0481b13b3a311901",
+        "version" : "4.2.1"
       }
     },
     {
diff --git a/Package.swift b/Package.swift
index e4ede22..ce02894 100644
--- a/Package.swift
+++ b/Package.swift
@@ -17,7 +17,7 @@ let package = Package(
         // Pinned exactly: the notarization broker builds with
         // `--only-use-versions-from-resolved-file` against its own copy of
         // Package.resolved.
-        .package(url: "https://github.com/mxcl/AppUpdater.git", exact: "4.1.2"),
+        .package(url: "https://github.com/mxcl/AppUpdater.git", exact: "4.2.1"),
         .package(url: "https://github.com/httpswift/swifter.git", exact: "1.5.0"),
     ],
     targets: [