diff --git a/.gitmodules b/.gitmodules
index cbf7a602..832b6423 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -791,3 +791,6 @@
 [submodule "vendor/grammars/language-babel"]
 	path = vendor/grammars/language-babel
 	url = https://github.com/github-linguist/language-babel
+[submodule "vendor/CodeMirror"]
+	path = vendor/CodeMirror
+	url = https://github.com/codemirror/CodeMirror
diff --git a/lib/linguist/language.rb b/lib/linguist/language.rb
index e823d6cf..875ef956 100644
--- a/lib/linguist/language.rb
+++ b/lib/linguist/language.rb
@@ -302,6 +302,7 @@ module Linguist
 
       @ace_mode = attributes[:ace_mode]
       @codemirror_mode = attributes[:codemirror_mode]
+      @codemirror_mime_type = attributes[:codemirror_mime_type]
       @wrap = attributes[:wrap] || false
 
       # Set legacy search term
@@ -399,7 +400,10 @@ module Linguist
     # Returns a String name or nil
     attr_reader :ace_mode
 
-    # Public: Get Codemirror mode
+    # Public: Get CodeMirror mode
+    #
+    # Maps to a directory in the `mode/` source code.
+    #   https://github.com/codemirror/CodeMirror/tree/master/mode
     #
     # Examples
     #
@@ -410,6 +414,17 @@ module Linguist
     # Returns a String name or nil
     attr_reader :codemirror_mode
 
+    # Public: Get CodeMirror MIME type mode
+    #
+    # Examples
+    #
+    #  # => "nil"
+    #  # => "text/x-javascript"
+    #  # => "text/x-csrc"
+    #
+    # Returns a String name or nil
+    attr_reader :codemirror_mime_type
+
     # Public: Should language lines be wrapped
     #
     # Returns true or false
@@ -587,6 +602,7 @@ module Linguist
       :tm_scope          => options['tm_scope'],
       :ace_mode          => options['ace_mode'],
       :codemirror_mode   => options['codemirror_mode'],
+      :codemirror_mime_type => options['codemirror_mime_type'],
       :wrap              => options['wrap'],
       :group_name        => options['group'],
       :searchable        => options.fetch('searchable', true),
diff --git a/lib/linguist/languages.yml b/lib/linguist/languages.yml
index 4bb5fbef..269525ce 100755
--- a/lib/linguist/languages.yml
+++ b/lib/linguist/languages.yml
@@ -6,7 +6,7 @@
 # ace_mode          - A String name of the Ace Mode used for highlighting whenever
 #                     a file is edited. This must match one of the filenames in http://git.io/3XO_Cg.
 #                     Use "text" if a mode does not exist.
-# codemirror_mode   - A String name of the Codemirror Mode used for highlighting whenever a file is edited.
+# codemirror_mode   - A String name of the CodeMirror Mode used for highlighting whenever a file is edited.
 #                     This must match a mode from https://git.io/vi9Fx
 # wrap              - Boolean wrap to enable line wrapping (default: false)
 # extensions        - An Array of associated extensions (the first one is
@@ -60,6 +60,7 @@ AGS Script:
   tm_scope: source.c++
   ace_mode: c_cpp
   codemirror_mode: clike
+  codemirror_mime_type: text/x-c++src
   language_id: 2
 AMPL:
   type: programming
@@ -98,6 +99,7 @@ APL:
   tm_scope: source.apl
   ace_mode: text
   codemirror_mode: apl
+  codemirror_mime_type: text/apl
   language_id: 6
 ASN.1:
   type: data
@@ -108,6 +110,7 @@ ASN.1:
   tm_scope: source.asn
   ace_mode: text
   codemirror_mode: asn.1
+  codemirror_mime_type: text/x-ttcn-asn
   language_id: 7
 ASP:
   type: programming
@@ -127,6 +130,7 @@ ASP:
   - ".axd"
   ace_mode: text
   codemirror_mode: htmlembedded
+  codemirror_mime_type: application/x-aspx
   language_id: 8
 ATS:
   type: programming
@@ -190,6 +194,7 @@ Alpine Abuild:
   tm_scope: source.shell
   ace_mode: sh
   codemirror_mode: shell
+  codemirror_mime_type: text/x-sh
   language_id: 14
 Ant Build System:
   type: data
@@ -199,6 +204,7 @@ Ant Build System:
   - build.xml
   ace_mode: xml
   codemirror_mode: xml
+  codemirror_mime_type: application/xml
   language_id: 15
 ApacheConf:
   type: markup
@@ -218,6 +224,7 @@ Apex:
   tm_scope: source.java
   ace_mode: java
   codemirror_mode: clike
+  codemirror_mime_type: text/x-java
   language_id: 17
 Apollo Guidance Computer:
   type: programming
@@ -227,7 +234,6 @@ Apollo Guidance Computer:
   - ".agc"
   tm_scope: source.agc
   ace_mode: assembly_x86
-  codemirror_mode:  gas
   language_id: 18
 AppleScript:
   type: programming
@@ -257,6 +263,7 @@ Arduino:
   tm_scope: source.c++
   ace_mode: c_cpp
   codemirror_mode: clike
+  codemirror_mime_type: text/x-c++src
   language_id: 21
 AsciiDoc:
   type: prose
@@ -289,7 +296,6 @@ Assembly:
   - ".nasm"
   tm_scope: source.assembly
   ace_mode: assembly_x86
-  codemirror_mode: gas
   language_id: 24
 Augeas:
   type: programming
@@ -428,6 +434,7 @@ Brainfuck:
   tm_scope: source.bf
   ace_mode: text
   codemirror_mode: brainfuck
+  codemirror_mime_type: text/x-brainfuck
   language_id: 38
 Brightscript:
   type: programming
@@ -455,11 +462,13 @@ C:
   - tcc
   ace_mode: c_cpp
   codemirror_mode: clike
+  codemirror_mime_type: text/x-csrc
   language_id: 41
 C#:
   type: programming
   ace_mode: csharp
   codemirror_mode: clike
+  codemirror_mime_type: text/x-csharp
   tm_scope: source.cs
   search_term: csharp
   color: "#178600"
@@ -475,6 +484,7 @@ C++:
   type: programming
   ace_mode: c_cpp
   codemirror_mode: clike
+  codemirror_mime_type: text/x-c++src
   search_term: cpp
   color: "#f34b7d"
   aliases:
@@ -502,7 +512,6 @@ C-ObjDump:
   - ".c-objdump"
   tm_scope: objdump.x86asm
   ace_mode: assembly_x86
-  codemirror_mode: gas
   language_id: 44
 C2hs Haskell:
   type: programming
@@ -514,6 +523,7 @@ C2hs Haskell:
   tm_scope: source.haskell
   ace_mode: haskell
   codemirror_mode: haskell
+  codemirror_mime_type: text/x-haskell
   language_id: 45
 CLIPS:
   type: programming
@@ -531,6 +541,7 @@ CMake:
   - CMakeLists.txt
   ace_mode: text
   codemirror_mode: cmake
+  codemirror_mime_type: text/x-cmake
   language_id: 47
 COBOL:
   type: programming
@@ -542,6 +553,7 @@ COBOL:
   - ".cpy"
   ace_mode: cobol
   codemirror_mode: cobol
+  codemirror_mime_type: text/x-cobol
   language_id: 48
 COLLADA:
   type: data
@@ -550,12 +562,14 @@ COLLADA:
   tm_scope: text.xml
   ace_mode: xml
   codemirror_mode: xml
+  codemirror_mime_type: text/xml
   language_id: 49
 CSS:
   type: markup
   tm_scope: source.css
   ace_mode: css
   codemirror_mode: css
+  codemirror_mime_type: text/css
   color: "#563d7c"
   extensions:
   - ".css"
@@ -612,6 +626,7 @@ ChucK:
   tm_scope: source.java
   ace_mode: java
   codemirror_mode: clike
+  codemirror_mime_type: text/x-java
   language_id: 57
 Cirru:
   type: programming
@@ -649,6 +664,7 @@ Clojure:
   type: programming
   ace_mode: clojure
   codemirror_mode: clojure
+  codemirror_mime_type: text/x-clojure
   color: "#db5855"
   extensions:
   - ".clj"
@@ -668,6 +684,7 @@ CoffeeScript:
   tm_scope: source.coffee
   ace_mode: coffee
   codemirror_mode: coffeescript
+  codemirror_mime_type: text/x-coffeescript
   color: "#244776"
   aliases:
   - coffee
@@ -734,6 +751,7 @@ Common Lisp:
   - ecl
   ace_mode: lisp
   codemirror_mode: commonlisp
+  codemirror_mime_type: text/x-common-lisp
   language_id: 66
 Component Pascal:
   type: programming
@@ -747,6 +765,7 @@ Component Pascal:
   - objectpascal
   ace_mode: pascal
   codemirror_mode: pascal
+  codemirror_mime_type: text/x-pascal
   language_id: 67
 Cool:
   type: programming
@@ -774,7 +793,6 @@ Cpp-ObjDump:
   aliases:
   - c++-objdump
   ace_mode: assembly_x86
-  codemirror_mode: gas
   language_id: 70
 Creole:
   type: prose
@@ -791,6 +809,7 @@ Crystal:
   - ".cr"
   ace_mode: ruby
   codemirror_mode: crystal
+  codemirror_mime_type: text/x-crystal
   tm_scope: source.crystal
   interpreters:
   - crystal
@@ -841,6 +860,7 @@ Cuda:
   tm_scope: source.cuda-c++
   ace_mode: c_cpp
   codemirror_mode: clike
+  codemirror_mime_type: text/x-c++src
   color: "#3A4E3A"
   language_id: 77
 Cycript:
@@ -850,6 +870,7 @@ Cycript:
   tm_scope: source.js
   ace_mode: javascript
   codemirror_mode: javascript
+  codemirror_mime_type: text/javascript
   language_id: 78
 Cython:
   type: programming
@@ -862,6 +883,7 @@ Cython:
   - pyrex
   ace_mode: text
   codemirror_mode: python
+  codemirror_mime_type: text/x-cython
   language_id: 79
 D:
   type: programming
@@ -871,6 +893,7 @@ D:
   - ".di"
   ace_mode: d
   codemirror_mode: d
+  codemirror_mime_type: text/x-d
   language_id: 80
 D-ObjDump:
   type: data
@@ -878,7 +901,6 @@ D-ObjDump:
   - ".d-objdump"
   tm_scope: objdump.x86asm
   ace_mode: assembly_x86
-  codemirror_mode: gas
   language_id: 81
 DIGITAL Command Language:
   type: programming
@@ -918,6 +940,7 @@ DTrace:
   tm_scope: source.c
   ace_mode: c_cpp
   codemirror_mode: clike
+  codemirror_mime_type: text/x-csrc
   language_id: 85
 Darcs Patch:
   type: data
@@ -939,6 +962,7 @@ Dart:
   - dart
   ace_mode: dart
   codemirror_mode: dart
+  codemirror_mime_type: application/dart
   language_id: 87
 Diff:
   type: data
@@ -950,6 +974,7 @@ Diff:
   tm_scope: source.diff
   ace_mode: diff
   codemirror_mode: diff
+  codemirror_mime_type: text/x-diff
   language_id: 88
 Dockerfile:
   type: data
@@ -960,6 +985,7 @@ Dockerfile:
   - Dockerfile
   ace_mode: dockerfile
   codemirror_mode: dockerfile
+  codemirror_mime_type: text/x-dockerfile
   language_id: 89
 Dogescript:
   type: programming
@@ -979,6 +1005,7 @@ Dylan:
   - ".lid"
   ace_mode: text
   codemirror_mode: dylan
+  codemirror_mime_type: text/x-dylan
   language_id: 91
 E:
   type: programming
@@ -999,6 +1026,7 @@ ECL:
   tm_scope: none
   ace_mode: text
   codemirror_mode: ecl
+  codemirror_mime_type: text/x-ecl
   language_id: 93
 ECLiPSe:
   type: programming
@@ -1025,6 +1053,7 @@ EQ:
   tm_scope: source.cs
   ace_mode: csharp
   codemirror_mode: clike
+  codemirror_mime_type: text/x-csharp
   language_id: 96
 Eagle:
   type: markup
@@ -1035,6 +1064,7 @@ Eagle:
   tm_scope: text.xml
   ace_mode: xml
   codemirror_mode: xml
+  codemirror_mime_type: text/xml
   language_id: 97
 Ecere Projects:
   type: data
@@ -1043,7 +1073,8 @@ Ecere Projects:
   - ".epj"
   tm_scope: source.json
   ace_mode: json
-  codemirror_mode: json
+  codemirror_mode: javascript
+  codemirror_mime_type: application/json
   language_id: 98
 Eiffel:
   type: programming
@@ -1052,6 +1083,7 @@ Eiffel:
   - ".e"
   ace_mode: eiffel
   codemirror_mode: eiffel
+  codemirror_mime_type: text/x-eiffel
   language_id: 99
 Elixir:
   type: programming
@@ -1073,6 +1105,7 @@ Elm:
   tm_scope: source.elm
   ace_mode: elm
   codemirror_mode: elm
+  codemirror_mime_type: text/x-elm
   language_id: 101
 Emacs Lisp:
   type: programming
@@ -1097,6 +1130,7 @@ Emacs Lisp:
   - ".emacs.desktop"
   ace_mode: lisp
   codemirror_mode: commonlisp
+  codemirror_mime_type: text/x-common-lisp
   language_id: 102
 EmberScript:
   type: programming
@@ -1107,6 +1141,7 @@ EmberScript:
   tm_scope: source.coffee
   ace_mode: coffee
   codemirror_mode: coffeescript
+  codemirror_mime_type: text/x-coffeescript
   language_id: 103
 Erlang:
   type: programming
@@ -1125,6 +1160,7 @@ Erlang:
   - rebar.lock
   ace_mode: erlang
   codemirror_mode: erlang
+  codemirror_mime_type: text/x-erlang
   interpreters:
   - escript
   language_id: 104
@@ -1141,6 +1177,7 @@ F#:
   tm_scope: source.fsharp
   ace_mode: text
   codemirror_mode: mllike
+  codemirror_mime_type: text/x-fsharp
   language_id: 105
 FLUX:
   type: programming
@@ -1166,6 +1203,7 @@ FORTRAN:
   tm_scope: source.fortran.modern
   ace_mode: text
   codemirror_mode: fortran
+  codemirror_mime_type: text/x-fortran
   language_id: 107
 Factor:
   type: programming
@@ -1177,6 +1215,7 @@ Factor:
   - ".factor-rc"
   ace_mode: text
   codemirror_mode: factor
+  codemirror_mime_type: text/x-factor
   language_id: 108
 Fancy:
   type: programming
@@ -1233,6 +1272,7 @@ Forth:
   - ".fs"
   ace_mode: forth
   codemirror_mode: forth
+  codemirror_mime_type: text/x-forth
   language_id: 114
 FreeMarker:
   type: programming
@@ -1287,7 +1327,6 @@ GAS:
   - ".ms"
   tm_scope: source.assembly
   ace_mode: assembly_x86
-  codemirror_mode: gas
   language_id: 120
 GCC Machine Description:
   type: programming
@@ -1296,6 +1335,7 @@ GCC Machine Description:
   tm_scope: source.lisp
   ace_mode: lisp
   codemirror_mode: commonlisp
+  codemirror_mime_type: text/x-common-lisp
   language_id: 121
 GDB:
   type: programming
@@ -1341,6 +1381,7 @@ Game Maker Language:
   tm_scope: source.c++
   ace_mode: c_cpp
   codemirror_mode: clike
+  codemirror_mime_type: text/x-c++src
   language_id: 125
 Genshi:
   type: programming
@@ -1352,6 +1393,7 @@ Genshi:
   - xml+kid
   ace_mode: xml
   codemirror_mode: xml
+  codemirror_mime_type: text/xml
   language_id: 126
 Gentoo Ebuild:
   type: programming
@@ -1361,6 +1403,7 @@ Gentoo Ebuild:
   tm_scope: source.shell
   ace_mode: sh
   codemirror_mode: shell
+  codemirror_mime_type: text/x-sh
   language_id: 127
 Gentoo Eclass:
   type: programming
@@ -1370,6 +1413,7 @@ Gentoo Eclass:
   tm_scope: source.shell
   ace_mode: sh
   codemirror_mode: shell
+  codemirror_mime_type: text/x-sh
   language_id: 128
 Gettext Catalog:
   type: prose
@@ -1391,6 +1435,7 @@ Glyph:
   tm_scope: source.tcl
   ace_mode: tcl
   codemirror_mode: tcl
+  codemirror_mime_type: text/x-tcl
   language_id: 130
 Gnuplot:
   type: programming
@@ -1412,6 +1457,7 @@ Go:
   - ".go"
   ace_mode: golang
   codemirror_mode: go
+  codemirror_mime_type: text/x-go
   language_id: 132
 Golo:
   type: programming
@@ -1458,6 +1504,7 @@ Grammatical Framework:
   tm_scope: source.haskell
   ace_mode: haskell
   codemirror_mode: haskell
+  codemirror_mime_type: text/x-haskell
   language_id: 137
 Graph Modeling Language:
   type: data
@@ -1518,11 +1565,13 @@ Groff:
   - troff
   ace_mode: text
   codemirror_mode: troff
+  codemirror_mime_type: text/troff
   language_id: 141
 Groovy:
   type: programming
   ace_mode: groovy
   codemirror_mode: groovy
+  codemirror_mime_type: text/x-groovy
   color: "#e69f56"
   extensions:
   - ".groovy"
@@ -1545,6 +1594,7 @@ Groovy Server Pages:
   tm_scope: text.html.jsp
   ace_mode: jsp
   codemirror_mode: htmlembedded
+  codemirror_mime_type: application/x-jsp
   language_id: 143
 HCL:
   type: programming
@@ -1553,6 +1603,7 @@ HCL:
   - ".tf"
   ace_mode: ruby
   codemirror_mode: ruby
+  codemirror_mime_type: text/x-ruby
   tm_scope: source.ruby
   language_id: 144
 HLSL:
@@ -1569,7 +1620,8 @@ HTML:
   type: markup
   tm_scope: text.html.basic
   ace_mode: html
-  codemirror_mode: html
+  codemirror_mode: htmlmixed
+  codemirror_mime_type: text/html
   color: "#e44b23"
   aliases:
   - xhtml
@@ -1596,6 +1648,7 @@ HTML+Django:
   - htmldjango
   ace_mode: django
   codemirror_mode: django
+  codemirror_mime_type: text/x-django
   language_id: 147
 HTML+ECR:
   type: markup
@@ -1606,7 +1659,8 @@ HTML+ECR:
   extensions:
   - ".ecr"
   ace_mode: text
-  codemirror_mode: htmlembedded
+  codemirror_mode: htmlmixed
+  codemirror_mime_type: text/html
   language_id: 148
 HTML+EEX:
   type: markup
@@ -1617,7 +1671,8 @@ HTML+EEX:
   extensions:
   - ".eex"
   ace_mode: text
-  codemirror_mode: htmlembedded
+  codemirror_mode: htmlmixed
+  codemirror_mime_type: text/html
   language_id: 149
 HTML+ERB:
   type: markup
@@ -1630,6 +1685,7 @@ HTML+ERB:
   - ".erb.deface"
   ace_mode: text
   codemirror_mode: htmlembedded
+  codemirror_mime_type: application/x-erb
   language_id: 150
 HTML+PHP:
   type: markup
@@ -1639,6 +1695,7 @@ HTML+PHP:
   - ".phtml"
   ace_mode: php
   codemirror_mode: php
+  codemirror_mime_type: application/x-httpd-php
   language_id: 151
 HTTP:
   type: data
@@ -1647,11 +1704,13 @@ HTTP:
   tm_scope: source.httpspec
   ace_mode: text
   codemirror_mode: http
+  codemirror_mime_type: message/http
   language_id: 152
 Hack:
   type: programming
   ace_mode: php
   codemirror_mode: php
+  codemirror_mime_type: application/x-httpd-php
   extensions:
   - ".hh"
   - ".php"
@@ -1666,6 +1725,7 @@ Haml:
   - ".haml.deface"
   ace_mode: haml
   codemirror_mode: haml
+  codemirror_mime_type: text/x-haml
   color: "#ECE2A9"
   language_id: 154
 Handlebars:
@@ -1680,7 +1740,6 @@ Handlebars:
   - ".hbs"
   tm_scope: text.html.handlebars
   ace_mode: handlebars
-  codemirror_mode: handlebars
   language_id: 155
 Harbour:
   type: programming
@@ -1700,11 +1759,13 @@ Haskell:
   - runhaskell
   ace_mode: haskell
   codemirror_mode: haskell
+  codemirror_mime_type: text/x-haskell
   language_id: 157
 Haxe:
   type: programming
   ace_mode: haxe
   codemirror_mode: haxe
+  codemirror_mime_type: text/x-haxe
   color: "#df7900"
   extensions:
   - ".hx"
@@ -1736,6 +1797,7 @@ IDL:
   - ".dlm"
   ace_mode: text
   codemirror_mode: idl
+  codemirror_mime_type: text/x-idl
   language_id: 161
 IGOR Pro:
   type: programming
@@ -1760,6 +1822,7 @@ INI:
   - dosini
   ace_mode: ini
   codemirror_mode: properties
+  codemirror_mime_type: text/x-properties
   language_id: 163
 IRC log:
   type: data
@@ -1860,6 +1923,7 @@ JSON:
   group: JavaScript
   ace_mode: json
   codemirror_mode: javascript
+  codemirror_mime_type: application/json
   searchable: false
   extensions:
   - ".json"
@@ -1879,12 +1943,12 @@ JSON5:
   tm_scope: source.js
   ace_mode: javascript
   codemirror_mode: javascript
+  codemirror_mime_type: application/json
   language_id: 175
 JSONLD:
   type: data
   group: JavaScript
   ace_mode: javascript
-  codemirror_mode: javascript
   extensions:
   - ".jsonld"
   tm_scope: source.js
@@ -1894,6 +1958,7 @@ JSONiq:
   type: programming
   ace_mode: jsoniq
   codemirror_mode: javascript
+  codemirror_mime_type: application/json
   extensions:
   - ".jq"
   tm_scope: source.jq
@@ -1905,6 +1970,8 @@ JSX:
   - ".jsx"
   tm_scope: source.js.jsx
   ace_mode: javascript
+  codemirror_mode: jsx
+  codemirror_mime_type: text/jsx
   language_id: 178
 Jade:
   group: HTML
@@ -1915,6 +1982,7 @@ Jade:
   tm_scope: text.jade
   ace_mode: jade
   codemirror_mode: pug
+  codemirror_mime_type: text/x-pug
   language_id: 179
 Jasmin:
   type: programming
@@ -1927,6 +1995,7 @@ Java:
   type: programming
   ace_mode: java
   codemirror_mode: clike
+  codemirror_mime_type: text/x-java
   color: "#b07219"
   extensions:
   - ".java"
@@ -1942,12 +2011,14 @@ Java Server Pages:
   tm_scope: text.html.jsp
   ace_mode: jsp
   codemirror_mode: htmlembedded
+  codemirror_mime_type: application/x-jsp
   language_id: 182
 JavaScript:
   type: programming
   tm_scope: source.js
   ace_mode: javascript
   codemirror_mode: javascript
+  codemirror_mime_type: text/javascript
   color: "#f1e05a"
   aliases:
   - js
@@ -1997,11 +2068,13 @@ Julia:
   color: "#a270ba"
   ace_mode: julia
   codemirror_mode: julia
+  codemirror_mime_type: text/x-julia
   language_id: 184
 Jupyter Notebook:
   type: markup
   ace_mode: json
   codemirror_mode: javascript
+  codemirror_mime_type: application/json
   tm_scope: source.json
   color: "#DA5B0B"
   extensions:
@@ -2031,7 +2104,8 @@ KiCad:
 Kit:
   type: markup
   ace_mode: html
-  codemirror_mode: html
+  codemirror_mode: htmlmixed
+  codemirror_mime_type: text/html
   extensions:
   - ".kit"
   tm_scope: text.html.basic
@@ -2045,7 +2119,8 @@ Kotlin:
   - ".kts"
   tm_scope: source.Kotlin
   ace_mode: text
-  codemirror_mode: kotlin
+  codemirror_mode: clike
+  codemirror_mime_type: text/x-kotlin
   language_id: 189
 LFE:
   type: programming
@@ -2056,6 +2131,7 @@ LFE:
   tm_scope: source.lisp
   ace_mode: lisp
   codemirror_mode: commonlisp
+  codemirror_mime_type: text/x-common-lisp
   language_id: 190
 LLVM:
   type: programming
@@ -2089,6 +2165,7 @@ LabVIEW:
   tm_scope: text.xml
   ace_mode: xml
   codemirror_mode: xml
+  codemirror_mime_type: text/xml
   language_id: 194
 Lasso:
   type: programming
@@ -2113,6 +2190,7 @@ Latte:
   tm_scope: text.html.smarty
   ace_mode: smarty
   codemirror_mode: smarty
+  codemirror_mime_type: text/x-smarty
   language_id: 196
 Lean:
   type: programming
@@ -2129,6 +2207,7 @@ Less:
   tm_scope: source.css.less
   ace_mode: less
   codemirror_mode: css
+  codemirror_mime_type: text/css
   color: "#A1D9A1"
   language_id: 198
 Lex:
@@ -2213,6 +2292,7 @@ Literate Haskell:
   tm_scope: text.tex.latex.haskell
   ace_mode: text
   codemirror_mode: haskell-literate
+  codemirror_mime_type: text/x-literate-haskell
   language_id: 207
 LiveScript:
   type: programming
@@ -2227,6 +2307,7 @@ LiveScript:
   - Slakefile
   ace_mode: livescript
   codemirror_mode: livescript
+  codemirror_mime_type: text/x-livescript
   language_id: 208
 Logos:
   type: programming
@@ -2248,6 +2329,7 @@ LookML:
   type: programming
   ace_mode: yaml
   codemirror_mode: yaml
+  codemirror_mime_type: text/x-yaml
   color: "#652B81"
   extensions:
   - ".lookml"
@@ -2264,6 +2346,7 @@ Lua:
   type: programming
   ace_mode: lua
   codemirror_mode: lua
+  codemirror_mime_type: text/x-lua
   color: "#000080"
   extensions:
   - ".lua"
@@ -2284,6 +2367,7 @@ M:
   - ".m"
   ace_mode: text
   codemirror_mode: mumps
+  codemirror_mime_type: text/x-mumps
   language_id: 214
   tm_scope: none
 M4:
@@ -2321,7 +2405,8 @@ MTML:
   - ".mtml"
   tm_scope: text.html.basic
   ace_mode: html
-  codemirror_mode: html
+  codemirror_mode: htmlmixed
+  codemirror_mime_type: text/html
   language_id: 218
 MUF:
   type: programming
@@ -2332,6 +2417,7 @@ MUF:
   tm_scope: none
   ace_mode: forth
   codemirror_mode: forth
+  codemirror_mime_type: text/x-forth
   language_id: 219
 Makefile:
   type: programming
@@ -2361,6 +2447,7 @@ Makefile:
   - make
   ace_mode: makefile
   codemirror_mode: cmake
+  codemirror_mime_type: text/x-cmake
   language_id: 220
 Mako:
   type: programming
@@ -2373,7 +2460,8 @@ Mako:
 Markdown:
   type: prose
   ace_mode: markdown
-  codemirror_mode: markdown
+  codemirror_mode: gfm
+  codemirror_mime_type: text/x-gfm
   wrap: true
   extensions:
   - ".md"
@@ -2408,6 +2496,7 @@ Mathematica:
   - mma
   ace_mode: text
   codemirror_mode: mathematica
+  codemirror_mime_type: text/x-mathematica
   language_id: 224
 Matlab:
   type: programming
@@ -2419,6 +2508,7 @@ Matlab:
   - ".m"
   ace_mode: matlab
   codemirror_mode: octave
+  codemirror_mime_type: text/x-octave
   language_id: 225
 Maven POM:
   type: data
@@ -2427,6 +2517,7 @@ Maven POM:
   - pom.xml
   ace_mode: xml
   codemirror_mode: xml
+  codemirror_mime_type: text/xml
   language_id: 226
 Max:
   type: programming
@@ -2444,6 +2535,7 @@ Max:
   tm_scope: source.json
   ace_mode: json
   codemirror_mode: javascript
+  codemirror_mime_type: application/json
   language_id: 227
 MediaWiki:
   type: prose
@@ -2473,6 +2565,7 @@ Metal:
   tm_scope: source.c++
   ace_mode: c_cpp
   codemirror_mode: clike
+  codemirror_mime_type: text/x-c++src
   language_id: 230
 MiniD:
   type: programming
@@ -2494,6 +2587,7 @@ Mirah:
   tm_scope: source.ruby
   ace_mode: ruby
   codemirror_mode: ruby
+  codemirror_mime_type: text/x-ruby
   language_id: 232
 Modelica:
   type: programming
@@ -2502,6 +2596,7 @@ Modelica:
   tm_scope: source.modelica
   ace_mode: text
   codemirror_mode: modelica
+  codemirror_mime_type: text/x-modelica
   language_id: 233
 Modula-2:
   type: programming
@@ -2572,6 +2667,7 @@ NSIS:
   - ".nsh"
   ace_mode: text
   codemirror_mode: nsis
+  codemirror_mime_type: text/x-nsis
   language_id: 242
 Nemerle:
   type: programming
@@ -2606,6 +2702,7 @@ NetLogo:
   tm_scope: source.lisp
   ace_mode: lisp
   codemirror_mode: commonlisp
+  codemirror_mime_type: text/x-common-lisp
   language_id: 246
 NewLisp:
   type: programming
@@ -2620,6 +2717,7 @@ NewLisp:
   tm_scope: source.lisp
   ace_mode: lisp
   codemirror_mode: commonlisp
+  codemirror_mime_type: text/x-common-lisp
   language_id: 247
 Nginx:
   type: markup
@@ -2633,6 +2731,7 @@ Nginx:
   - nginx configuration file
   ace_mode: text
   codemirror_mode: nginx
+  codemirror_mime_type: text/x-nginx-conf
   color: "#9469E9"
   language_id: 248
 Nimrod:
@@ -2681,6 +2780,7 @@ Nu:
   tm_scope: source.nu
   ace_mode: scheme
   codemirror_mode: scheme
+  codemirror_mime_type: text/x-scheme
   interpreters:
   - nush
   language_id: 253
@@ -2694,12 +2794,14 @@ NumPy:
   tm_scope: none
   ace_mode: text
   codemirror_mode: python
+  codemirror_mime_type: text/x-python
   color: "#9C8AF9"
   language_id: 254
 OCaml:
   type: programming
   ace_mode: ocaml
   codemirror_mode: mllike
+  codemirror_mime_type: text/x-ocaml
   color: "#3be133"
   extensions:
   - ".ml"
@@ -2721,7 +2823,6 @@ ObjDump:
   - ".objdump"
   tm_scope: objdump.x86asm
   ace_mode: assembly_x86
-  codemirror_mode: gas
   language_id: 256
 Objective-C:
   type: programming
@@ -2736,6 +2837,7 @@ Objective-C:
   - ".h"
   ace_mode: objectivec
   codemirror_mode: clike
+  codemirror_mime_type: text/x-objectivec
   language_id: 257
 Objective-C++:
   type: programming
@@ -2749,6 +2851,7 @@ Objective-C++:
   - ".mm"
   ace_mode: objectivec
   codemirror_mode: clike
+  codemirror_mime_type: text/x-objectivec
   language_id: 258
 Objective-J:
   type: programming
@@ -2794,6 +2897,7 @@ OpenCL:
   tm_scope: source.c
   ace_mode: c_cpp
   codemirror_mode: clike
+  codemirror_mime_type: text/x-csrc
   language_id: 263
 OpenEdge ABL:
   type: programming
@@ -2817,6 +2921,7 @@ OpenRC runscript:
   tm_scope: source.shell
   ace_mode: sh
   codemirror_mode: shell
+  codemirror_mime_type: text/x-sh
   language_id: 265
 OpenSCAD:
   type: programming
@@ -2858,6 +2963,7 @@ Oz:
   tm_scope: source.oz
   ace_mode: text
   codemirror_mode: oz
+  codemirror_mime_type: text/x-oz
   language_id: 270
 PAWN:
   type: programming
@@ -2873,6 +2979,7 @@ PHP:
   tm_scope: text.html.php
   ace_mode: php
   codemirror_mode: php
+  codemirror_mime_type: application/x-httpd-php
   color: "#4F5D95"
   extensions:
   - ".php"
@@ -2896,6 +3003,7 @@ PLSQL:
   type: programming
   ace_mode: sql
   codemirror_mode: sql
+  codemirror_mime_type: text/x-plsql
   tm_scope: none
   color: "#dad8d8"
   extensions:
@@ -2911,6 +3019,7 @@ PLpgSQL:
   type: programming
   ace_mode: pgsql
   codemirror_mode: sql
+  codemirror_mime_type: text/x-sql
   tm_scope: source.sql
   extensions:
   - ".sql"
@@ -2988,12 +3097,14 @@ Pascal:
   - instantfpc
   ace_mode: pascal
   codemirror_mode: pascal
+  codemirror_mime_type: text/x-pascal
   language_id: 281
 Perl:
   type: programming
   tm_scope: source.perl
   ace_mode: perl
   codemirror_mode: perl
+  codemirror_mime_type: text/x-perl
   color: "#0298c3"
   extensions:
   - ".pl"
@@ -3032,6 +3143,7 @@ Perl6:
   tm_scope: source.perl6fe
   ace_mode: perl
   codemirror_mode: perl
+  codemirror_mime_type: text/x-perl
   language_id: 283
 Pickle:
   type: data
@@ -3072,6 +3184,7 @@ Pod:
   type: prose
   ace_mode: perl
   codemirror_mode: perl
+  codemirror_mime_type: text/x-perl
   wrap: true
   extensions:
   - ".pod"
@@ -3118,6 +3231,7 @@ PowerShell:
   type: programming
   ace_mode: powershell
   codemirror_mode: powershell
+  codemirror_mime_type: application/x-powershell
   aliases:
   - posh
   extensions:
@@ -3164,6 +3278,7 @@ Protocol Buffer:
   tm_scope: source.protobuf
   ace_mode: protobuf
   codemirror_mode: protobuf
+  codemirror_mime_type: text/x-protobuf
   language_id: 297
 Public Key:
   type: data
@@ -3182,6 +3297,7 @@ Puppet:
   - Modulefile
   ace_mode: text
   codemirror_mode: puppet
+  codemirror_mime_type: text/x-puppet
   tm_scope: source.puppet
   language_id: 299
 Pure Data:
@@ -3209,11 +3325,13 @@ PureScript:
   tm_scope: source.purescript
   ace_mode: haskell
   codemirror_mode: haskell
+  codemirror_mime_type: text/x-haskell
   language_id: 302
 Python:
   type: programming
   ace_mode: python
   codemirror_mode: python
+  codemirror_mime_type: text/x-python
   color: "#3572A5"
   extensions:
   - ".py"
@@ -3289,11 +3407,13 @@ R:
   - Rscript
   ace_mode: r
   codemirror_mode: r
+  codemirror_mime_type: text/x-rsrc
   language_id: 307
 RAML:
   type: markup
   ace_mode: yaml
   codemirror_mode: yaml
+  codemirror_mime_type: text/x-yaml
   tm_scope: source.yaml
   color: "#77d9fb"
   extensions:
@@ -3340,12 +3460,14 @@ RHTML:
   - html+ruby
   ace_mode: rhtml
   codemirror_mode: htmlembedded
+  codemirror_mime_type: application/x-erb
   language_id: 312
 RMarkdown:
   type: prose
   wrap: true
   ace_mode: markdown
-  codemirror_mode: markdown
+  codemirror_mode: gfm
+  codemirror_mime_type: text/x-gfm
   extensions:
   - ".rmd"
   tm_scope: source.gfm
@@ -3359,6 +3481,7 @@ RPM Spec:
   - specfile
   ace_mode: text
   codemirror_mode: rpm
+  codemirror_mime_type: text/x-rpm-spec
   language_id: 314
 RUNOFF:
   type: markup
@@ -3462,6 +3585,7 @@ Rouge:
   type: programming
   ace_mode: clojure
   codemirror_mode: clojure
+  codemirror_mime_type: text/x-clojure
   color: "#cc0088"
   extensions:
   - ".rg"
@@ -3471,6 +3595,7 @@ Ruby:
   type: programming
   ace_mode: ruby
   codemirror_mode: ruby
+  codemirror_mime_type: text/x-ruby
   color: "#701516"
   aliases:
   - jruby
@@ -3533,6 +3658,7 @@ Rust:
   - ".rs.in"
   ace_mode: rust
   codemirror_mode: rust
+  codemirror_mime_type: text/x-rustsrc
   language_id: 327
 SAS:
   type: programming
@@ -3542,6 +3668,7 @@ SAS:
   tm_scope: source.sas
   ace_mode: text
   codemirror_mode: sas
+  codemirror_mime_type: text/x-sas
   language_id: 328
 SCSS:
   type: markup
@@ -3549,6 +3676,7 @@ SCSS:
   group: CSS
   ace_mode: scss
   codemirror_mode: css
+  codemirror_mime_type: text/x-scss
   extensions:
   - ".scss"
   color: "#CF649A"
@@ -3577,6 +3705,7 @@ SPARQL:
   tm_scope: source.sparql
   ace_mode: text
   codemirror_mode: sparql
+  codemirror_mime_type: application/sparql-query
   extensions:
   - ".sparql"
   - ".rq"
@@ -3595,6 +3724,7 @@ SQL:
   tm_scope: source.sql
   ace_mode: sql
   codemirror_mode: sql
+  codemirror_mime_type: text/x-sql
   extensions:
   - ".sql"
   - ".cql"
@@ -3609,6 +3739,7 @@ SQLPL:
   type: programming
   ace_mode: sql
   codemirror_mode: sql
+  codemirror_mime_type: text/x-sql
   tm_scope: source.sql
   extensions:
   - ".sql"
@@ -3620,6 +3751,7 @@ SRecode Template:
   tm_scope: source.lisp
   ace_mode: lisp
   codemirror_mode: commonlisp
+  codemirror_mime_type: text/x-common-lisp
   extensions:
   - ".srt"
   language_id: 335
@@ -3638,6 +3770,7 @@ SVG:
   tm_scope: text.xml
   ace_mode: xml
   codemirror_mode: xml
+  codemirror_mime_type: text/xml
   language_id: 337
 Sage:
   type: programming
@@ -3648,6 +3781,7 @@ Sage:
   tm_scope: source.python
   ace_mode: python
   codemirror_mode: python
+  codemirror_mime_type: text/x-python
   language_id: 338
 SaltStack:
   type: programming
@@ -3660,6 +3794,7 @@ SaltStack:
   tm_scope: source.yaml.salt
   ace_mode: yaml
   codemirror_mode: yaml
+  codemirror_mime_type: text/x-yaml
   language_id: 339
 Sass:
   type: markup
@@ -3669,12 +3804,14 @@ Sass:
   - ".sass"
   ace_mode: sass
   codemirror_mode: sass
+  codemirror_mime_type: text/x-sass
   color: "#CF649A"
   language_id: 340
 Scala:
   type: programming
   ace_mode: scala
   codemirror_mode: clike
+  codemirror_mime_type: text/x-scala
   color: "#c22d40"
   extensions:
   - ".scala"
@@ -3709,6 +3846,7 @@ Scheme:
   - r6rs
   ace_mode: scheme
   codemirror_mode: scheme
+  codemirror_mime_type: text/x-scheme
   language_id: 343
 Scilab:
   type: programming
@@ -3761,6 +3899,7 @@ Shell:
   - zsh
   ace_mode: sh
   codemirror_mode: shell
+  codemirror_mime_type: text/x-sh
   language_id: 346
 ShellSession:
   type: programming
@@ -3772,6 +3911,7 @@ ShellSession:
   tm_scope: text.shell-session
   ace_mode: sh
   codemirror_mode: shell
+  codemirror_mime_type: text/x-sh
   language_id: 347
 Shen:
   type: programming
@@ -3798,6 +3938,7 @@ Slim:
   tm_scope: text.slim
   ace_mode: text
   codemirror_mode: slim
+  codemirror_mime_type: text/x-slim
   language_id: 350
 Smali:
   type: programming
@@ -3816,6 +3957,7 @@ Smalltalk:
   - squeak
   ace_mode: text
   codemirror_mode: smalltalk
+  codemirror_mime_type: text/x-stsrc
   language_id: 352
 Smarty:
   type: programming
@@ -3823,6 +3965,7 @@ Smarty:
   - ".tpl"
   ace_mode: smarty
   codemirror_mode: smarty
+  codemirror_mime_type: text/x-smarty
   tm_scope: text.html.smarty
   language_id: 353
 SourcePawn:
@@ -3845,6 +3988,7 @@ Squirrel:
   tm_scope: source.c++
   ace_mode: c_cpp
   codemirror_mode: clike
+  codemirror_mime_type: text/x-c++src
   language_id: 355
 Stan:
   type: programming
@@ -3867,6 +4011,7 @@ Standard ML:
   tm_scope: source.ml
   ace_mode: text
   codemirror_mode: mllike
+  codemirror_mime_type: text/x-ocaml
   language_id: 357
 Stata:
   type: programming
@@ -3887,7 +4032,6 @@ Stylus:
   - ".styl"
   tm_scope: source.stylus
   ace_mode: stylus
-  codemirror_mode: stylus
   language_id: 359
 SubRip Text:
   type: data
@@ -3915,6 +4059,7 @@ Swift:
   - ".swift"
   ace_mode: text
   codemirror_mode: swift
+  codemirror_mime_type: text/x-swift
   language_id: 362
 SystemVerilog:
   type: programming
@@ -3925,6 +4070,7 @@ SystemVerilog:
   - ".vh"
   ace_mode: verilog
   codemirror_mode: verilog
+  codemirror_mime_type: text/x-systemverilog
   language_id: 363
 TLA:
   type: programming
@@ -3940,6 +4086,7 @@ TOML:
   tm_scope: source.toml
   ace_mode: toml
   codemirror_mode: toml
+  codemirror_mime_type: text/x-toml
   language_id: 365
 TXL:
   type: programming
@@ -3960,6 +4107,7 @@ Tcl:
   - wish
   ace_mode: tcl
   codemirror_mode: tcl
+  codemirror_mime_type: text/x-tcl
   language_id: 367
 Tcsh:
   type: programming
@@ -3970,12 +4118,14 @@ Tcsh:
   tm_scope: source.shell
   ace_mode: sh
   codemirror_mode: shell
+  codemirror_mime_type: text/x-sh
   language_id: 368
 TeX:
   type: markup
   color: "#3D6117"
   ace_mode: tex
   codemirror_mode: stex
+  codemirror_mime_type: text/x-stex
   wrap: true
   aliases:
   - latex
@@ -4010,6 +4160,7 @@ Terra:
   color: "#00004c"
   ace_mode: lua
   codemirror_mode: lua
+  codemirror_mime_type: text/x-lua
   interpreters:
   - lua
   language_id: 371
@@ -4043,6 +4194,7 @@ Textile:
   type: prose
   ace_mode: textile
   codemirror_mode: textile
+  codemirror_mime_type: text/x-textile
   wrap: true
   extensions:
   - ".textile"
@@ -4071,6 +4223,7 @@ Turtle:
   tm_scope: source.turtle
   ace_mode: text
   codemirror_mode: turtle
+  codemirror_mime_type: text/turtle
   language_id: 376
 Twig:
   type: markup
@@ -4080,6 +4233,7 @@ Twig:
   tm_scope: text.html.twig
   ace_mode: twig
   codemirror_mode: twig
+  codemirror_mime_type: text/x-twig
   language_id: 377
 TypeScript:
   type: programming
@@ -4092,12 +4246,14 @@ TypeScript:
   tm_scope: source.ts
   ace_mode: typescript
   codemirror_mode: javascript
+  codemirror_mime_type: application/typescript
   language_id: 378
 Unified Parallel C:
   type: programming
   group: C
   ace_mode: c_cpp
   codemirror_mode: clike
+  codemirror_mime_type: text/x-csrc
   color: "#4e3617"
   extensions:
   - ".upc"
@@ -4107,6 +4263,7 @@ Unity3D Asset:
   type: data
   ace_mode: yaml
   codemirror_mode: yaml
+  codemirror_mime_type: text/x-yaml
   extensions:
   - ".anim"
   - ".asset"
@@ -4122,6 +4279,7 @@ Uno:
   - ".uno"
   ace_mode: csharp
   codemirror_mode: clike
+  codemirror_mime_type: text/x-csharp
   tm_scope: source.cs
   language_id: 381
 UnrealScript:
@@ -4132,6 +4290,7 @@ UnrealScript:
   tm_scope: source.java
   ace_mode: java
   codemirror_mode: clike
+  codemirror_mime_type: text/x-java
   language_id: 382
 UrWeb:
   type: programming
@@ -4166,6 +4325,7 @@ VHDL:
   - ".vhw"
   ace_mode: vhdl
   codemirror_mode: vhdl
+  codemirror_mime_type: text/x-vhdl
   language_id: 385
 Vala:
   type: programming
@@ -4183,6 +4343,7 @@ Verilog:
   - ".veo"
   ace_mode: verilog
   codemirror_mode: verilog
+  codemirror_mime_type: text/x-verilog
   language_id: 387
 VimL:
   type: programming
@@ -4221,6 +4382,7 @@ Visual Basic:
   - vbnet
   ace_mode: text
   codemirror_mode: vb
+  codemirror_mime_type: text/x-vb
   language_id: 389
 Volt:
   type: programming
@@ -4230,6 +4392,7 @@ Volt:
   tm_scope: source.d
   ace_mode: d
   codemirror_mode: d
+  codemirror_mime_type: text/x-d
   language_id: 390
 Vue:
   type: markup
@@ -4238,7 +4401,6 @@ Vue:
   - ".vue"
   tm_scope: text.html.vue
   ace_mode: html
-  codemirror_mode: vue
   language_id: 391
 Wavefront Material:
   type: data
@@ -4269,6 +4431,7 @@ WebIDL:
   tm_scope: source.webidl
   ace_mode: text
   codemirror_mode: webidl
+  codemirror_mime_type: text/x-webidl
   language_id: 395
 World of Warcraft Addon Data:
   type: data
@@ -4295,11 +4458,13 @@ XC:
   tm_scope: source.xc
   ace_mode: c_cpp
   codemirror_mode: clike
+  codemirror_mime_type: text/x-csrc
   language_id: 398
 XML:
   type: data
   ace_mode: xml
   codemirror_mode: xml
+  codemirror_mime_type: text/xml
   aliases:
   - rss
   - xsd
@@ -4409,6 +4574,7 @@ XPages:
   tm_scope: none
   ace_mode: xml
   codemirror_mode: xml
+  codemirror_mime_type: text/xml
   language_id: 400
 XProc:
   type: programming
@@ -4418,6 +4584,7 @@ XProc:
   tm_scope: text.xml
   ace_mode: xml
   codemirror_mode: xml
+  codemirror_mime_type: text/xml
   language_id: 401
 XQuery:
   type: programming
@@ -4430,6 +4597,7 @@ XQuery:
   - ".xqy"
   ace_mode: xquery
   codemirror_mode: xquery
+  codemirror_mime_type: application/xquery
   tm_scope: source.xq
   language_id: 402
 XS:
@@ -4439,6 +4607,7 @@ XS:
   tm_scope: source.c
   ace_mode: c_cpp
   codemirror_mode: clike
+  codemirror_mime_type: text/x-csrc
   language_id: 403
 XSLT:
   type: programming
@@ -4450,6 +4619,7 @@ XSLT:
   tm_scope: text.xml.xsl
   ace_mode: xml
   codemirror_mode: xml
+  codemirror_mime_type: text/xml
   color: "#EB8CEB"
   language_id: 404
 Xojo:
@@ -4487,6 +4657,7 @@ YAML:
   - ".clang-format"
   ace_mode: yaml
   codemirror_mode: yaml
+  codemirror_mime_type: text/x-yaml
   language_id: 407
 YANG:
   type: data
@@ -4544,6 +4715,7 @@ edn:
   type: data
   ace_mode: clojure
   codemirror_mode: clojure
+  codemirror_mime_type: text/x-clojure
   extensions:
   - ".edn"
   tm_scope: source.clojure
@@ -4592,10 +4764,13 @@ reStructuredText:
   - ".rst.txt"
   ace_mode: text
   codemirror_mode: rst
+  codemirror_mime_type: text/x-rst
   language_id: 419
 wisp:
   type: programming
   ace_mode: clojure
+  codemirror_mode: clojure
+  codemirror_mime_type: text/x-clojure
   color: "#7582D1"
   extensions:
   - ".wisp"
diff --git a/lib/linguist/vendor.yml b/lib/linguist/vendor.yml
index 6b8c7364..e500f85d 100644
--- a/lib/linguist/vendor.yml
+++ b/lib/linguist/vendor.yml
@@ -165,7 +165,7 @@
 # Chart.js
 - (^|/)Chart\.js$
 
-# Codemirror
+# CodeMirror
 - (^|/)[Cc]ode[Mm]irror/(\d+\.\d+/)?(lib|mode|theme|addon|keymap|demo)
 
 # SyntaxHighlighter - http://alexgorbatchev.com/
diff --git a/test/test_file_blob.rb b/test/test_file_blob.rb
index 383b170e..84cee723 100644
--- a/test/test_file_blob.rb
+++ b/test/test_file_blob.rb
@@ -317,7 +317,7 @@ class TestFileBlob < Minitest::Test
     assert sample_blob("some/vendored/path/Chart.js").vendored?
     assert !sample_blob("some/vendored/path/chart.js").vendored?
 
-    # Codemirror deps
+    # CodeMirror deps
     assert sample_blob("codemirror/mode/blah.js").vendored?
     assert sample_blob("codemirror/5.0/mode/blah.js").vendored?
 
diff --git a/test/test_grammars.rb b/test/test_grammars.rb
index 3b03ca81..1b878847 100644
--- a/test/test_grammars.rb
+++ b/test/test_grammars.rb
@@ -126,7 +126,7 @@ class TestGrammars < Minitest::Test
   private
 
   def submodule_paths
-    @submodule_paths ||= `git config --list --file "#{File.join(ROOT, ".gitmodules")}"`.lines.grep(/\.path=/).map { |line| line.chomp.split("=", 2).last }
+    @submodule_paths ||= `git config --list --file "#{File.join(ROOT, ".gitmodules")}"`.lines.grep(/\.path=/).map { |line| line.chomp.split("=", 2).last }.reject { |path| path =~ /CodeMirror/ }
   end
 
   # Returns a hash of submodules in the form of submodule_path => license
diff --git a/test/test_language.rb b/test/test_language.rb
index 1456fb84..1f6d19d2 100644
--- a/test/test_language.rb
+++ b/test/test_language.rb
@@ -352,9 +352,19 @@ class TestLanguage < Minitest::Test
   end
 
   def test_codemirror_mode
+    assert_equal 'ruby', Language['Ruby'].codemirror_mode
+    assert_equal 'javascript', Language['JavaScript'].codemirror_mode
+    assert_equal 'clike', Language['C'].codemirror_mode
     assert_equal 'clike', Language['C++'].codemirror_mode
   end
 
+  def test_codemirror_mime_type
+    assert_equal 'text/x-ruby', Language['Ruby'].codemirror_mime_type
+    assert_equal 'text/javascript', Language['JavaScript'].codemirror_mime_type
+    assert_equal 'text/x-csrc', Language['C'].codemirror_mime_type
+    assert_equal 'text/x-c++src', Language['C++'].codemirror_mime_type
+  end
+
   def test_wrap
     assert_equal false, Language['C'].wrap
     assert_equal true, Language['Markdown'].wrap
@@ -442,6 +452,40 @@ class TestLanguage < Minitest::Test
     assert missing.empty?, message
   end
 
+  def test_codemirror_modes_present
+    Language.all.each do |language|
+      if language.codemirror_mode || language.codemirror_mime_type
+        assert language.codemirror_mode, "#{language.inspect} missing CodeMirror mode"
+        assert language.codemirror_mime_type, "#{language.inspect} missing CodeMirror MIME mode"
+      end
+    end
+  end
+
+  def test_valid_codemirror_mode
+    Language.all.each do |language|
+      if mode = language.codemirror_mode
+        assert File.exist?(File.expand_path("../../vendor/CodeMirror/mode/#{mode}", __FILE__)), "#{mode} isn't a valid CodeMirror mode"
+      end
+    end
+  end
+
+  def test_codemirror_mode_and_mime_defined_by_meta_mapping
+    meta = File.read(File.expand_path("../../vendor/CodeMirror/mode/meta.js", __FILE__))
+    Language.all.each do |language|
+      next unless language.codemirror_mode && language.codemirror_mime_type
+      assert meta.match(/^.+#{Regexp.escape(language.codemirror_mime_type)}.+#{Regexp.escape(language.codemirror_mode)}.+$/), "#{language.inspect}: #{language.codemirror_mime_type} not defined under #{language.codemirror_mode}"
+    end
+  end
+
+  def test_codemirror_mime_declared_in_mode_file
+    Language.all.each do |language|
+      next unless language.codemirror_mode && language.codemirror_mime_type
+      filename = File.expand_path("../../vendor/CodeMirror/mode/#{language.codemirror_mode}/#{language.codemirror_mode}.js", __FILE__)
+      assert File.exist?(filename), "#{filename} does not exist"
+      assert File.read(filename).match(language.codemirror_mime_type), "#{language.inspect}: #{language.codemirror_mime_type} not defined in #{filename}"
+    end
+  end
+
   def test_all_popular_languages_exist
     popular = YAML.load(File.read(File.expand_path("../../lib/linguist/popular.yml", __FILE__)))
 
diff --git a/vendor/CodeMirror b/vendor/CodeMirror
new file mode 160000
index 00000000..562e8eff
--- /dev/null
+++ b/vendor/CodeMirror
@@ -0,0 +1 @@
+Subproject commit 562e8eff5b0916d3b63fc59eda9540f8f455c6ed