diff --git a/Package.resolved b/Package.resolved
new file mode 100644
index 0000000..8b9e8bf
--- /dev/null
+++ b/Package.resolved
@@ -0,0 +1,14 @@
+{
+  "pins" : [
+    {
+      "identity" : "swift-collections",
+      "kind" : "remoteSourceControl",
+      "location" : "https://github.com/apple/swift-collections.git",
+      "state" : {
+        "revision" : "8c0c0a8b49e080e54e5e328cc552821ff07cd341",
+        "version" : "1.2.1"
+      }
+    }
+  ],
+  "version" : 2
+}