diff --git a/Cargo.toml b/Cargo.toml
index 9743a84..4d73f66 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -21,7 +21,7 @@ parking_lot = "0.12.2"
 criterion = "0.5.1"
 
 # minimal versions
-clap_builder = "=4.5.20" # MSRV <= 1.70.0
+clap_builder = "=4.5.21" # MSRV <= 1.70.0
 
 # overridden versions
 bumpalo = "3.16.0" # yanked: "3.15.0"