diff --git a/Project.toml b/Project.toml
index 00b2b85..f62be72 100644
--- a/Project.toml
+++ b/Project.toml
@@ -22,6 +22,7 @@ Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 Combinatorics = "^1"
 Formatting = "^0.4.1"
 GaussianBasis = "^0.4"
+KrylovKit = "0.5"
 LoopVectorization = "0.12"
 Molecules = "0.3"
 Octavian = "0.3"