diff --git a/tools/gn/xcode_object.cc b/tools/gn/xcode_object.cc
index 3e9dd2c..ab056b2 100644
--- a/tools/gn/xcode_object.cc
+++ b/tools/gn/xcode_object.cc
@@ -98,6 +98,7 @@
 const SourceTypeForExt kSourceTypeForExt[] = {
     {".a", "archive.ar"},
     {".app", "wrapper.application"},
+    {".appex", "wrapper.app-extension"},
     {".bdic", "file"},
     {".bundle", "wrapper.cfbundle"},
     {".c", "sourcecode.c.c"},