diff --git a/test/Project.toml b/test/Project.toml
index 2f1c5a31..ea55ae83 100644
--- a/test/Project.toml
+++ b/test/Project.toml
@@ -43,6 +43,7 @@ LazyArrays = "1, 2"
 LogDensityProblems = "2"
 LogExpFunctions = "0.3.1"
 MCMCDiagnosticTools = "0.3"
+Mooncake = "0.4"
 ReverseDiff = "1.4.2"
 StableRNGs = "1"
 Tracker = "0.2.11"