diff --git a/Project.toml b/Project.toml
index b258b95..53d2126 100644
--- a/Project.toml
+++ b/Project.toml
@@ -19,6 +19,7 @@ UnitfulAtomic = "a7773ee8-282e-5fa2-be4e-bd808c38a91a"
 ElectricFields = "0.1, 0.2"
 FastGaussQuadrature = "0.4.7, 0.5"
 HCubature = "1.5"
+IntervalSets = "0.7"
 SpecialFunctions = "1.3,2"
 StaticArrays = "1.1"
 Unitful = "1.7"