diff --git a/Project.toml b/Project.toml
index 56b0e13..f4e6196 100644
--- a/Project.toml
+++ b/Project.toml
@@ -16,6 +16,7 @@ CategoricalArrays = "0.5, 0.6, 0.7"
 CodecZlib = "0.4, 0.5, 0.6"
 DataFrames = "0.19, 0.20"
 FileIO = "1.0.5"
+Requires = "1.0.0"
 TimeZones = "0.7, 0.8, 0.9, 0.10"
 julia = "1"