diff --git a/bucket/mdbook.json b/bucket/mdbook.json
index a4b1feaca4..3bcd3277bd 100644
--- a/bucket/mdbook.json
+++ b/bucket/mdbook.json
@@ -1,12 +1,12 @@
 {
-    "version": "0.4.11",
+    "version": "0.4.12",
     "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/v0.4.11/mdbook-v0.4.11-x86_64-pc-windows-msvc.zip",
-            "hash": "2e8aa0458b90d1a282aeeee83af660b5e8013fd315609e1c45c88009f31adfae"
+            "url": "https://github.com/rust-lang/mdBook/releases/download/v0.4.12/mdbook-v0.4.12-x86_64-pc-windows-msvc.zip",
+            "hash": "114d7f2bfadeadb417d22a627ebe141dbedcf1b98c3060eeca198fe7e35e94b7"
         }
     },
     "bin": "mdbook.exe",