diff --git a/Project.toml b/Project.toml
index 3e32622..a84c517 100644
--- a/Project.toml
+++ b/Project.toml
@@ -12,6 +12,7 @@ SparseArrays = "2f01184e-e22b-5df5-ae63-d93ebab69eaf"
 Symbolics = "0c5d862f-8b57-4792-8d23-62f2024744c7"
 
 [compat]
+NLsolve = "4"
 julia = "1"
 
 [extras]