diff --git a/test/Project.toml b/test/Project.toml
index ed991c0c0..3a35bb387 100644
--- a/test/Project.toml
+++ b/test/Project.toml
@@ -27,6 +27,7 @@ GeoParams = "0.5, 0.6"
 JustPIC = "0.3.4, 0.3.5, 0.3.6, 0.4"
 MPI = "0.20"
 ParallelStencil = "0.11, 0.12, 0.13"
+SpecialFunctions = "2"
 StaticArrays = "1"
 Statistics = "1"
 Suppressor = "0.2"