diff --git a/bucket/mdbook.json b/bucket/mdbook.json
index d7292dff71..04185fc590 100644
--- a/bucket/mdbook.json
+++ b/bucket/mdbook.json
@@ -1,12 +1,12 @@
 {
-    "version": "0.4.30",
+    "version": "0.4.31",
     "description": "Create a book from markdown files.",
     "homepage": "https://github.com/rust-lang/mdBook",
     "license": "MPL-2.0",
     "architecture": {
         "64bit": {
-            "url": "https://github.com/rust-lang/mdBook/releases/download/v0.4.30/mdbook-v0.4.30-x86_64-pc-windows-msvc.zip",
-            "hash": "50c1adcabb37e291b9689b76898e91bf98428e5d5335dd3724f7c223f7a9ebb1"
+            "url": "https://github.com/rust-lang/mdBook/releases/download/v0.4.31/mdbook-v0.4.31-x86_64-pc-windows-msvc.zip",
+            "hash": "f55c476e298b53d9724933b8a0df5d150f5340ac8a08b64405e402846c3ac5b4"
         }
     },
     "bin": "mdbook.exe",