diff --git a/docs/_setup.R b/docs/_setup.R
index 10cd1a5ab68535d2c252e60a7561de1685db56ab..a33b10f2d2cbc13e470bce38e55139c2624e61c6 100644
--- a/docs/_setup.R
+++ b/docs/_setup.R
@@ -33,6 +33,7 @@ opts_chunk$set(
     message = FALSE,
     echo = FALSE,
     tidy = TRUE,
+    cache = TRUE,
     fig.width = 7,
     fig.height = 5,
     fig.align = "center",