diff --git a/HISTORY.md b/HISTORY.md
index c59ba57c9..b99fd471b 100644
--- a/HISTORY.md
+++ b/HISTORY.md
@@ -1,6 +1,7 @@
 unreleased
 ==========
 
+  * Add `application/ubjson` with extension `.ubj`
   * Add new upstream MIME types
   * Fix extension of `application/vnd.apple.keynote` to be `.key`
 
diff --git a/db.json b/db.json
index a0d90e35f..2caed645d 100644
--- a/db.json
+++ b/db.json
@@ -1611,6 +1611,10 @@
   "application/tzif-leap": {
     "source": "iana"
   },
+  "application/ubjson": {
+    "compressible": false,
+    "extensions": ["ubj"]
+  },
   "application/ulpfec": {
     "source": "iana"
   },
diff --git a/src/custom-types.json b/src/custom-types.json
index 5c36373b2..dd3d741bb 100644
--- a/src/custom-types.json
+++ b/src/custom-types.json
@@ -152,6 +152,13 @@
     ],
     "compressible": true
   },
+  "application/ubjson": {
+    "extensions": ["ubj"],
+    "sources" : [
+      "http://ubjson.org/"
+    ],
+    "compressible": false
+  },
   "application/vnd.android.package-archive": {
     "compressible": false
   },