diff --git a/Project.toml b/Project.toml
index eee23e3df..a0dd4bf75 100644
--- a/Project.toml
+++ b/Project.toml
@@ -39,7 +39,7 @@ VegaLite = "112f6efa-9a02-5b7d-90c0-432ed331239a"
 CSVFiles = "0.16, 1.0"
 Classes = "1.2"
 Compose = "0.7, 0.8"
-DataFrames = "0.19.1, 0.20"
+DataFrames = "0.19.1, 0.20, 0.21"
 DataStructures = "0.17"
 Distributions = "0.21, 0.22, 0.23"
 Electron = "1.1, 2.0"