diff --git a/Project.toml b/Project.toml
index f1fbd2c..b09e499 100644
--- a/Project.toml
+++ b/Project.toml
@@ -19,3 +19,6 @@ Revise = "295af30f-e4ad-537b-8983-00126c2a3abe"
 SparseArrays = "2f01184e-e22b-5df5-ae63-d93ebab69eaf"
 StatsBase = "2913bbd2-ae8a-5f71-8c99-4fb6c76f3a91"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
+
+[compat]
+NLsolve = "4"