diff --git a/Project.toml b/Project.toml
index 7adf7ee..3b8ea91 100644
--- a/Project.toml
+++ b/Project.toml
@@ -13,6 +13,7 @@ Requires = "ae029012-a4dd-5104-9daa-d747884805df"
 [compat]
 AbstractMCMC = "1"
 Distributions = "0.20, 0.21, 0.22, 0.23"
+ForwardDiff = "0.10"
 Requires = "1.0"
 julia = "1"