diff --git a/Project.toml b/Project.toml
index 9650217..9021ac9 100644
--- a/Project.toml
+++ b/Project.toml
@@ -54,6 +54,7 @@ CSV = "0.7, 0.8, 0.9.11"
 DataFrames = "0.20, 0.21, 0.22, 0.23, 0.24, 1, 1.1"
 EchelleCCFs = ">=0.2.6"
 EchelleInstruments = ">=0.2.7"
+FITSIO = "0.17"
 FileIO = "1.4"
 JLD2 = "0.4"
 LsqFit = "0.12"