diff --git a/Project.toml b/Project.toml
index 3835f43..4b30c58 100644
--- a/Project.toml
+++ b/Project.toml
@@ -39,6 +39,7 @@ FastGaussQuadrature = "1"
 FiniteDiff = "2"
 FixedPoint = "1"
 ForwardDiff = "0.10"
+ImplicitAD = "0.3"
 LaTeXStrings = "1"
 LineSearches = "7"
 MINPACK = "1"