diff --git a/prost-build/Cargo.toml b/prost-build/Cargo.toml
index 2f9fc7c..71c5020 100644
--- a/prost-build/Cargo.toml
+++ b/prost-build/Cargo.toml
@@ -32,7 +32,7 @@ prettyplease = { version = "0.2", optional = true }
 syn = { version = "2", features = ["full"], optional = true }
 
 # These two must be kept in sync, used for `cleanup-markdown` feature.
-pulldown-cmark = { version = "0.12", optional = true, default-features = false }
+pulldown-cmark = { version = "0.13", optional = true, default-features = false }
 pulldown-cmark-to-cmark = { version = ">=16, <=17", optional = true }
 
 [dev-dependencies]