diff --git a/CHANGELOG.md b/CHANGELOG.md
index aa35bd39..a4a9ee04 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,8 @@ Note: In this file, do not use the hard wrap in the middle of a sentence for com
 
 ## [Unreleased]
 
+- Update `wasmtime@latest` to 21.0.0.
+
 ## [2.33.26] - 2024-05-19
 
 - Update `cargo-careful@latest` to 0.4.2.
diff --git a/manifests/wasmtime.json b/manifests/wasmtime.json
index 1e1c2a22..d9a317a6 100644
--- a/manifests/wasmtime.json
+++ b/manifests/wasmtime.json
@@ -23,7 +23,30 @@
     }
   },
   "latest": {
-    "version": "20.0.2"
+    "version": "21.0.0"
+  },
+  "21": {
+    "version": "21.0.0"
+  },
+  "21.0": {
+    "version": "21.0.0"
+  },
+  "21.0.0": {
+    "x86_64_linux_gnu": {
+      "checksum": "605efdd4d073a7574b6d42ef0c9037c6c4e3933ed80615eab84f2d57cfeb3b28"
+    },
+    "x86_64_macos": {
+      "checksum": "7beb9f1b6789af74beef8354b675d5cab6477be708bf45aa86f411c4afe55dfd"
+    },
+    "x86_64_windows": {
+      "checksum": "e57345a2bd644e7f4d0a013617d64a3e16966b9483fee72bad2ab1eebabce59b"
+    },
+    "aarch64_linux_gnu": {
+      "checksum": "0fa42c4555617cb4a602216ec45b8dc43686733653ec07f9488ab5e2e3bf5ec8"
+    },
+    "aarch64_macos": {
+      "checksum": "b4a09d69c2cb4655e68895156a1de713b27a6e64796d9073108d20f55b8d5d5c"
+    }
   },
   "20": {
     "version": "20.0.2"