diff --git a/Project.toml b/Project.toml
index a50b885..9a4af06 100644
--- a/Project.toml
+++ b/Project.toml
@@ -29,5 +29,5 @@ DualNumbers = "0.6"
 FastTransforms = "0.8"
 FillArrays = "0.6,0.7,0.8"
 SingularIntegralEquations = "0.6"
-SpecialFunctions = "0.7,0.8,0.9"
+SpecialFunctions = "0.7,0.8,0.9, 2"
 julia = "1.3"