diff --git a/test/Project.toml b/test/Project.toml
index 47a6aa4..a190b50 100644
--- a/test/Project.toml
+++ b/test/Project.toml
@@ -22,6 +22,7 @@ ChainRulesCore = "1"
 ChainRulesTestUtils = "1.9.2"
 Combinatorics = "1.0.2"
 Distributions = "0.25.15"
+Documenter = "1"
 FiniteDifferences = "0.11.3, 0.12"
 ForwardDiff = "0.10.12"
 LazyArrays = "1, 2"