diff --git a/test/Project.toml b/test/Project.toml
index de1dbd0d6..494a071a6 100644
--- a/test/Project.toml
+++ b/test/Project.toml
@@ -28,5 +28,5 @@ Kronecker = "0.4"
 LogExpFunctions = "0.2, 0.3"
 PDMats = "0.9, 0.10, 0.11"
 ReverseDiff = "1.2"
-SpecialFunctions = "0.10, 1"
+SpecialFunctions = "0.10, 1, 2"
 Zygote = "0.4, 0.5, 0.6"