diff --git a/DESCRIPTION b/DESCRIPTION
index 08aa574..eb44ce2 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -13,6 +13,7 @@ Description: Convert a data frame (containing a panel dataset, where rows
     "slopegraph" using either base or ggplot2 graphics.
 Imports:
     stats,
+    methods,
     utils,
     graphics,
     dplyr,