diff --git a/overrides/build-systems.json b/overrides/build-systems.json
index f5beb0062..81a4b60a1 100644
--- a/overrides/build-systems.json
+++ b/overrides/build-systems.json
@@ -19592,7 +19592,14 @@
     "setuptools"
   ],
   "willow": [
-    "setuptools"
+    {
+      "buildSystem": "setuptools",
+      "until": "1.6"
+    },
+    {
+      "buildSystem": "flit-core",
+      "from": "1.6"
+    }
   ],
   "winacl": [
     "setuptools"