diff --git a/lib/linguist/languages.yml b/lib/linguist/languages.yml
index b8230b6b..26a01d16 100644
--- a/lib/linguist/languages.yml
+++ b/lib/linguist/languages.yml
@@ -45,6 +45,7 @@ APL:
   extensions:
   - .apl
   - .dyalog
+  tm_scope: NONE
 
 ASP:
   type: programming
@@ -146,6 +147,7 @@ Arc:
   color: "#ca2afe"
   extensions:
   - .arc
+  tm_scope: NONE
 
 Arduino:
   type: programming
@@ -162,12 +164,14 @@ AsciiDoc:
   - .asciidoc
   - .adoc
   - .asc
+  tm_scope: NONE
 
 AspectJ:
   type: programming
   color: "#1957b0"
   extensions:
   - .aj
+  tm_scope: NONE
 
 Assembly:
   type: programming
@@ -185,6 +189,7 @@ Augeas:
   type: programming
   extensions:
   - .aug
+  tm_scope: NONE
 
 AutoHotkey:
   type: programming
@@ -194,6 +199,7 @@ AutoHotkey:
   extensions:
   - .ahk
   - .ahkl
+  tm_scope: NONE
 
 AutoIt:
   type: programming
@@ -286,6 +292,7 @@ Brightscript:
   type: programming
   extensions:
   - .brs
+  tm_scope: NONE
 
 Bro:
   type: programming
@@ -359,6 +366,7 @@ CLIPS:
   type: programming
   extensions:
   - .clp
+  tm_scope: NONE
 
 CMake:
   extensions:
@@ -421,6 +429,7 @@ Clean:
   extensions:
   - .icl
   - .dcl
+  tm_scope: NONE
 
 Clojure:
   type: programming
@@ -537,6 +546,7 @@ Creole:
   wrap: true
   extensions:
   - .creole
+  tm_scope: NONE
 
 Crystal:
   type: programming
@@ -604,6 +614,7 @@ Darcs Patch:
   extensions:
   - .darcspatch
   - .dpatch
+  tm_scope: NONE
 
 Dart:
   type: programming
@@ -631,6 +642,7 @@ Dogescript:
   color: "#cca760"
   extensions:
   - .djs
+  tm_scope: NONE
 
 Dylan:
   type: programming
@@ -646,6 +658,7 @@ E:
   color: "#ccce35"
   extensions:
   - .E
+  tm_scope: NONE
 
 ECL:
   type: programming
@@ -653,6 +666,7 @@ ECL:
   extensions:
   - .ecl
   - .eclxml
+  tm_scope: NONE
 
 Eagle:
   type: markup
@@ -736,6 +750,7 @@ FLUX:
   extensions:
   - .fx
   - .flux
+  tm_scope: NONE
 
 FORTRAN:
   type: programming
@@ -809,11 +824,13 @@ G-code:
   - .g
   - .gco
   - .gcode
+  tm_scope: NONE
 
 GAMS:
   type: programming
   extensions:
   - .gms
+  tm_scope: NONE
 
 GAP:
   type: programming
@@ -822,6 +839,7 @@ GAP:
   - .gap
   - .gd
   - .gi
+  tm_scope: NONE
 
 GAS:
   type: programming
@@ -835,6 +853,7 @@ GDScript:
   type: programming
   extensions:
   - .gd
+  tm_scope: NONE
 
 GLSL:
   group: C
@@ -919,6 +938,7 @@ Golo:
   color: "#f6a51f"
   extensions:
   - .golo
+  tm_scope: NONE
 
 Gosu:
   type: programming
@@ -934,6 +954,7 @@ Grace:
   type: programming
   extensions:
   - .grace
+  tm_scope: NONE
 
 Grammatical Framework:
   type: programming
@@ -950,6 +971,7 @@ Graph Modeling Language:
   type: data
   extensions:
   - .gml
+  tm_scope: NONE
 
 Graphviz (DOT):
   type: data
@@ -1039,6 +1061,7 @@ HTTP:
   type: data
   extensions:
   - .http
+  tm_scope: NONE
 
 Hack:
   type: programming
@@ -1046,6 +1069,7 @@ Hack:
   extensions:
   - .hh
   - .php
+  tm_scope: NONE
 
 Haml:
   group: HTML
@@ -1068,6 +1092,7 @@ Harbour:
   color: "#0e60e3"
   extensions:
   - .hb
+  tm_scope: NONE
 
 Haskell:
   type: programming
@@ -1093,6 +1118,7 @@ Hy:
   - .hy
   aliases:
   - hylang
+  tm_scope: NONE
 
 IDL:
   type: programming
@@ -1108,6 +1134,7 @@ IGOR Pro:
   aliases:
   - igor
   - igorpro
+  tm_scope: NONE
 
 INI:
   type: data
@@ -1128,6 +1155,7 @@ IRC log:
   extensions:
   - .irclog
   - .weechatlog
+  tm_scope: NONE
 
 Idris:
   type: programming
@@ -1149,6 +1177,7 @@ Inform 7:
 Inno Setup:
   extensions:
   - .iss
+  tm_scope: NONE
 
 Io:
   type: programming
@@ -1167,11 +1196,13 @@ Isabelle:
   color: "#fdcd00"
   extensions:
   - .thy
+  tm_scope: NONE
 
 J:
   type: programming
   extensions:
   - .ijs
+  tm_scope: NONE
 
 JSON:
   type: data
@@ -1279,6 +1310,7 @@ KRL:
   color: "#f5c800"
   extensions:
   - .krl
+  tm_scope: NONE
 
 Kit:
   type: markup
@@ -1312,6 +1344,7 @@ LOLCODE:
   extensions:
   - .lol
   color: "#cc9900"
+  tm_scope: NONE
 
 LSL:
   type: programming
@@ -1326,6 +1359,7 @@ LabVIEW:
   type: programming
   extensions:
   - .lvproj
+  tm_scope: NONE
 
 Lasso:
   type: programming
@@ -1364,12 +1398,14 @@ Liquid:
   type: markup
   extensions:
   - .liquid
+  tm_scope: NONE
 
 Literate Agda:
   type: programming
   group: Agda
   extensions:
   - .lagda
+  tm_scope: NONE
 
 Literate CoffeeScript:
   type: programming
@@ -1546,6 +1582,7 @@ MediaWiki:
   wrap: true
   extensions:
   - .mediawiki
+  tm_scope: NONE
 
 Mercury:
   type: programming
@@ -1560,6 +1597,7 @@ MiniD: # Legacy
   searchable: false
   extensions:
   - .minid # Dummy extension
+  tm_scope: NONE
 
 Mirah:
   type: programming
@@ -1581,6 +1619,7 @@ Moocode:
   type: programming
   extensions:
   - .moo
+  tm_scope: NONE
 
 MoonScript:
   type: programming
@@ -1592,6 +1631,7 @@ MoonScript:
 Myghty:
   extensions:
   - .myt
+  tm_scope: NONE
 
 NSIS:
   extensions:
@@ -1637,6 +1677,7 @@ Nit:
   color: "#0d8921"
   extensions:
   - .nit
+  tm_scope: NONE
 
 Nix:
   type: programming
@@ -1644,6 +1685,7 @@ Nix:
   - .nix
   aliases:
   - nixos
+  tm_scope: NONE
 
 Nu:
   type: programming
@@ -1662,6 +1704,7 @@ NumPy:
   - .numpy
   - .numpyw
   - .numsc
+  tm_scope: NONE
 
 OCaml:
   type: programming
@@ -1722,6 +1765,7 @@ Omgrofl:
   extensions:
   - .omgrofl
   color: "#cabbff"
+  tm_scope: NONE
 
 Opa:
   type: programming
@@ -1733,6 +1777,7 @@ Opal:
   color: "#f7ede0"
   extensions:
   - .opal
+  tm_scope: NONE
 
 OpenCL:
   type: programming
@@ -1757,12 +1802,14 @@ OpenSCAD:
   type: programming
   extensions:
   - .scad
+  tm_scope: NONE
 
 Org:
   type: prose
   wrap: true
   extensions:
   - .org
+  tm_scope: NONE
 
 Ox:
   type: programming
@@ -1770,12 +1817,14 @@ Ox:
   - .ox
   - .oxh
   - .oxo
+  tm_scope: NONE
 
 Oxygene:
   type: programming
   color: "#5a63a3"
   extensions:
   - .oxygene
+  tm_scope: NONE
 
 PAWN:
   type: programming
@@ -1811,18 +1860,21 @@ Pan:
   color: '#cc0000'
   extensions:
   - .pan
+  tm_scope: NONE
 
 Papyrus:
   type: programming
   color: "#6600cc"
   extensions:
   - .psc
+  tm_scope: NONE
 
 Parrot:
   type: programming
   color: "#f3ca0a"
   extensions:
   - .parrot # Dummy extension
+  tm_scope: NONE
 
 Parrot Assembly:
   group: Parrot
@@ -1831,6 +1883,7 @@ Parrot Assembly:
   - pasm
   extensions:
   - .pasm
+  tm_scope: NONE
 
 Parrot Internal Representation:
   group: Parrot
@@ -1882,12 +1935,14 @@ Perl6:
   - .p6m
   - .pl6
   - .pm6
+  tm_scope: NONE
 
 PigLatin:
   type: programming
   color: "#fcd7de"
   extensions:
   - .pig
+  tm_scope: NONE
 
 Pike:
   type: programming
@@ -1902,12 +1957,14 @@ Pod:
   wrap: true
   extensions:
   - .pod
+  tm_scope: NONE
 
 PogoScript:
   type: programming
   color: "#d80074"
   extensions:
   - .pogo
+  tm_scope: NONE
 
 PostScript:
   type: markup
@@ -1948,6 +2005,7 @@ Propeller Spin:
   color: "#2b446d"
   extensions:
   - .spin
+  tm_scope: NONE
 
 Protocol Buffer:
   type: markup
@@ -1971,6 +2029,7 @@ Pure Data:
   color: "#91de79"
   extensions:
   - .pd
+  tm_scope: NONE
 
 PureScript:
   type: programming
@@ -2077,6 +2136,7 @@ RMarkdown:
   extensions:
   - .rmd
   - .Rmd
+  tm_scope: NONE
 
 Racket:
   type: programming
@@ -2096,6 +2156,7 @@ Ragel in Ruby Host:
   aliases:
   - ragel-rb
   - ragel-ruby
+  tm_scope: NONE
 
 Raw token data:
   search_term: raw
@@ -2103,6 +2164,7 @@ Raw token data:
   - raw
   extensions:
   - .raw
+  tm_scope: NONE
 
 Rebol:
   type: programming
@@ -2122,10 +2184,12 @@ Red:
   - .reds
   aliases:
   - red/system
+  tm_scope: NONE
 
 Redcode:
   extensions:
   - .cw
+  tm_scope: NONE
 
 RobotFramework:
   type: programming
@@ -2199,6 +2263,7 @@ SAS:
   color: "#1E90FF"
   extensions:
   - .sas
+  tm_scope: NONE
 
 SCSS:
   type: markup
@@ -2292,6 +2357,7 @@ Self:
   color: "#0579aa"
   extensions:
   - .self
+  tm_scope: NONE
 
 Shell:
   type: programming
@@ -2330,6 +2396,7 @@ Shen:
   color: "#120F14"
   extensions:
   - .shen
+  tm_scope: NONE
 
 Slash:
   type: programming
@@ -2400,6 +2467,7 @@ Stylus:
   group: CSS
   extensions:
   - .styl
+  tm_scope: NONE
 
 SuperCollider:
   type: programming
@@ -2407,6 +2475,7 @@ SuperCollider:
   extensions:
   - .scd
   - .sc
+  tm_scope: NONE
 
 Swift:
   type: programming
@@ -2432,6 +2501,7 @@ TXL:
   type: programming
   extensions:
   - .txl
+  tm_scope: NONE
 
 Tcl:
   type: programming
@@ -2488,6 +2558,7 @@ Textile:
   wrap: true
   extensions:
   - .textile
+  tm_scope: NONE
 
 Thrift:
   type: programming
@@ -2501,6 +2572,7 @@ Turing:
   extensions:
   - .t
   - .tu
+  tm_scope: NONE
 
 Twig:
   type: markup
@@ -2761,6 +2833,7 @@ Zimpl:
   - .zimpl
   - .zmpl
   - .zpl
+  tm_scope: NONE
 
 eC:
   type: programming
@@ -2768,6 +2841,7 @@ eC:
   extensions:
   - .ec
   - .eh
+  tm_scope: NONE
 
 edn:
   type: data
@@ -2782,6 +2856,7 @@ fish:
   group: Shell
   extensions:
   - .fish
+  tm_scope: NONE
 
 mupad:
   extensions:
@@ -2822,3 +2897,4 @@ xBase:
   color: "#3a4040"
   extensions:
   - .prg
+  tm_scope: NONE
diff --git a/test/test_language.rb b/test/test_language.rb
index a23715d2..8dd4f97b 100644
--- a/test/test_language.rb
+++ b/test/test_language.rb
@@ -1,5 +1,6 @@
 require 'linguist/language'
 require 'test/unit'
+require 'yaml'
 
 class TestLanguage < Test::Unit::TestCase
   include Linguist
@@ -359,4 +360,15 @@ class TestLanguage < Test::Unit::TestCase
   def test_by_type
     assert !Language.by_type(:prose).nil?
   end
+
+  def test_all_languages_have_grammars
+    scopes = YAML.load(File.read(File.expand_path("../../grammars.yml", __FILE__))).values.flatten
+    missing = Language.all.reject { |language| language.tm_scope == "NONE" || scopes.include?(language.tm_scope) }
+    message = "The following languages' scopes are not listed in grammars.yml. Please add grammars for all new languages.\n"
+    message << "If no grammar exists for a language, mark the language with `tm_scope: NONE` in lib/linguist/languages.yml.\n"
+
+    width = missing.map { |language| language.name.length }.max
+    message << missing.map { |language| sprintf("%-#{width}s %s", language.name, language.tm_scope) }.sort.join("\n")
+    assert missing.empty?, message
+  end
 end