diff --git a/dev/bots/docs.sh b/dev/bots/docs.sh
index ee4acb5e0b8..f0f5bb9dc5a 100755
--- a/dev/bots/docs.sh
+++ b/dev/bots/docs.sh
@@ -63,7 +63,7 @@ if [[ -d "$FLUTTER_PUB_CACHE" ]]; then
 fi
 
 # Install and activate dartdoc.
-"$PUB" global activate dartdoc 0.20.4
+"$PUB" global activate dartdoc 0.21.1
 
 # This script generates a unified doc set, and creates
 # a custom index.html, placing everything into dev/docs/doc.