diff --git a/docs/Project.toml b/docs/Project.toml
index f346065a9..7d5b9f74c 100644
--- a/docs/Project.toml
+++ b/docs/Project.toml
@@ -7,6 +7,7 @@ Markdown = "d6f4376e-aef5-505a-96c1-9c027394607a"
 Plots = "91a5bcdd-55d7-5caf-9e0b-520d859cae80"
 
 [compat]
+ChainRulesCore = "1"
 Compat = "4"
 DocThemeIndigo = "0.1.3"
 Documenter = "1"