diff --git a/Project.toml b/Project.toml
index 82cd151492..7ff1bc1b62 100644
--- a/Project.toml
+++ b/Project.toml
@@ -25,7 +25,7 @@ GeneralizedGenerated = "0.1.4, 0.2"
 Latexify = "0.11, 0.12"
 MacroTools = "0.5"
 NaNMath = "0.3"
-SpecialFunctions = "0.7, 0.8"
+SpecialFunctions = "0.7, 0.8, 0.9"
 StaticArrays = "0.10, 0.11, 0.12"
 julia = "1"