diff --git a/Project.toml b/Project.toml
index b14cedd..d9b01c6 100644
--- a/Project.toml
+++ b/Project.toml
@@ -6,6 +6,7 @@ version = "1.0.0"
 [deps]
 Distributions = "31c24e10-a181-5473-b8eb-7969acd0382f"
 Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
+SpecialFunctions = "276daf66-3868-5448-9aa4-cd146d93841b"
 Statistics = "10745b16-79ce-11e8-11f9-7d13ad32a3b2"
 StatsAPI = "82ae8749-77ed-4fe6-ae5f-f523153014b0"
 StatsBase = "2913bbd2-ae8a-5f71-8c99-4fb6c76f3a91"
@@ -17,6 +18,7 @@ Random = "1.9"
 Statistics = "1.9"
 StatsAPI = "1.7"
 StatsBase = "0.34"
+SpecialFunctions = "2.3"
 TinyHugeNumbers = "1.0"
 julia = "1.9"