diff --git a/go.mod b/go.mod
index d2321c8..e7afe8f 100644
--- a/go.mod
+++ b/go.mod
@@ -6,7 +6,7 @@ require (
 	golang.org/x/sync v0.8.0
 )
 
-require github.com/creachadair/mds v0.21.2
+require github.com/creachadair/mds v0.21.3
 
 go 1.23
 
diff --git a/go.sum b/go.sum
index 5f00e1b..8c592e5 100644
--- a/go.sum
+++ b/go.sum
@@ -1,5 +1,5 @@
-github.com/creachadair/mds v0.21.2 h1:D5130qi/kqmu+gGUQyDNOhrocGQp075ziTCgttxhh3k=
-github.com/creachadair/mds v0.21.2/go.mod h1:1ltMWZd9yXhaHEoZwBialMaviWVUpRPvMwVP7saFAzM=
+github.com/creachadair/mds v0.21.3 h1:RRgEAPIb52cU0q7UxGyN+13QlCVTZIL4slRr0cYYQfA=
+github.com/creachadair/mds v0.21.3/go.mod h1:1ltMWZd9yXhaHEoZwBialMaviWVUpRPvMwVP7saFAzM=
 github.com/fortytw2/leaktest v1.3.0 h1:u8491cBMTQ8ft8aeV+adlcytMZylmA5nnwwkRZjI8vw=
 github.com/fortytw2/leaktest v1.3.0/go.mod h1:jDsjWgpAGjm2CA7WthBh/CdZYEPF31XHquHwclZch5g=
 github.com/google/go-cmp v0.6.0 h1:ofyhxvXcZhMsU5ulbFiLKl/XBFqE1GSq7atu8tAmTRI=
diff --git a/tools/go.mod b/tools/go.mod
index 89cca3e..ba046d3 100644
--- a/tools/go.mod
+++ b/tools/go.mod
@@ -11,6 +11,6 @@ require (
 
 require (
 	github.com/coder/websocket v1.8.12 // indirect
-	github.com/creachadair/mds v0.21.2 // indirect
+	github.com/creachadair/mds v0.21.3 // indirect
 	golang.org/x/sync v0.8.0 // indirect
 )
diff --git a/tools/go.sum b/tools/go.sum
index 2553a22..78edb60 100644
--- a/tools/go.sum
+++ b/tools/go.sum
@@ -2,8 +2,8 @@ github.com/coder/websocket v1.8.12 h1:5bUXkEPPIbewrnkU8LTCLVaxi4N4J8ahufH2vlo4NA
 github.com/coder/websocket v1.8.12/go.mod h1:LNVeNrXQZfe5qhS9ALED3uA+l5pPqvwXg3CKoDBB2gs=
 github.com/creachadair/jrpc2 v1.2.1 h1:eIgmguoqLbEjn4Pb/XYMg5U1PhVpAClGdhI/Q4gfC5o=
 github.com/creachadair/jrpc2 v1.2.1/go.mod h1:RvEKAYVpDBKn3YWlTVQJIFmxG5GuLD7ztp9FMTJx8eI=
-github.com/creachadair/mds v0.21.2 h1:D5130qi/kqmu+gGUQyDNOhrocGQp075ziTCgttxhh3k=
-github.com/creachadair/mds v0.21.2/go.mod h1:1ltMWZd9yXhaHEoZwBialMaviWVUpRPvMwVP7saFAzM=
+github.com/creachadair/mds v0.21.3 h1:RRgEAPIb52cU0q7UxGyN+13QlCVTZIL4slRr0cYYQfA=
+github.com/creachadair/mds v0.21.3/go.mod h1:1ltMWZd9yXhaHEoZwBialMaviWVUpRPvMwVP7saFAzM=
 github.com/creachadair/wschannel v0.0.0-20240812143019-767d903641b9 h1:RmzgVZNFyAkv9ogYygr4+8a7ohY2AFIIr5mcxJITh3I=
 github.com/creachadair/wschannel v0.0.0-20240812143019-767d903641b9/go.mod h1:y1EUhJKHdMHM+/6l+5hz/wh9IDT/5L8U3TAQS1IWwcE=
 github.com/fortytw2/leaktest v1.3.0 h1:u8491cBMTQ8ft8aeV+adlcytMZylmA5nnwwkRZjI8vw=