diff --git a/Project.toml b/Project.toml
index 959b74a..af383fc 100644
--- a/Project.toml
+++ b/Project.toml
@@ -12,3 +12,6 @@ QuadGK = "1fd47b50-473d-5c70-9696-f719f8f3bcdc"
 SCS = "c946c3f1-0d1f-5ce8-9dea-7daa1f7e2d13"
 SpecialFunctions = "276daf66-3868-5448-9aa4-cd146d93841b"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
+
+[compat]
+NonNegLeastSquares = "0.4"