diff --git a/Project.toml b/Project.toml
index 91b1647..7fb1a05 100644
--- a/Project.toml
+++ b/Project.toml
@@ -18,6 +18,7 @@ Statistics = "10745b16-79ce-11e8-11f9-7d13ad32a3b2"
 Compose = "0.9"
 DataStructures = "0.17, 0.18"
 Distributions = "0.23"
+Gadfly = "1.3"
 LayeredLayouts = "0.1.0"
 LightGraphs = "1"
 RecipesBase = "1"