diff --git a/rebar.config b/rebar.config
index fcd4eba..4ecbf72 100644
--- a/rebar.config
+++ b/rebar.config
@@ -17,7 +17,7 @@
   {rebar3_format, "~> 1.3.0"},
   {rebar3_lint, "~> 3.1.0"},
   {rebar3_sheldon, "~> 0.4.3"},
-  {rebar3_ex_doc, "~> 0.2.20"}]}.
+  {rebar3_ex_doc, "~> 0.2.21"}]}.
 
 {dialyzer,
  [{warnings,