diff --git a/Project.toml b/Project.toml
index 82a1045..66bf4b1 100644
--- a/Project.toml
+++ b/Project.toml
@@ -38,6 +38,7 @@ FastGaussQuadrature = "1"
 FiniteDiff = "2"
 FixedPoint = "1"
 ForwardDiff = "0.10"
+ImplicitAD = "0.3"
 LineSearches = "7"
 MINPACK = "1"
 NLsolve = "4"