diff --git a/Project.toml b/Project.toml
index e0a0663..d7e2a59 100644
--- a/Project.toml
+++ b/Project.toml
@@ -11,6 +11,7 @@ StaticArrays = "90137ffa-7385-5640-81b9-e52037218182"
 WriteVTK = "64499a7a-5c06-52f2-abe2-ccb03c286192"
 
 [compat]
+DualNumbers = "0.6"
 julia = "1.6"
 
 [extras]