diff --git a/Project.toml b/Project.toml
index a597ab1..9a191fa 100644
--- a/Project.toml
+++ b/Project.toml
@@ -33,7 +33,7 @@ PSFModels = "0.1"
 PaddedViews = "0.5"
 Photometry = "0.7"
 Rotations = "1"
-SpecialFunctions = "0.10, 1"
+SpecialFunctions = "0.10, 1, 2"
 StaticArrays = "0.12, 1.0"
 StatsBase = "0.32, 0.33"
 julia = "1.3"