diff --git a/script/list-grammars b/script/list-grammars
index b573c7ed..1e82d78d 100755
--- a/script/list-grammars
+++ b/script/list-grammars
@@ -99,4 +99,8 @@ class GrammarList
 end
 
 list = GrammarList.new
-list.update_readme()
+if ARGV.include? "--print"
+  puts list.to_markdown
+else
+  list.update_readme
+end
diff --git a/test/test_grammars.rb b/test/test_grammars.rb
index 14f4199e..80550acb 100644
--- a/test/test_grammars.rb
+++ b/test/test_grammars.rb
@@ -90,7 +90,7 @@ class TestGrammars < Minitest::Test
       message << unlisted_submodules.sort.join("\n")
     end
 
-    assert nonexistent_submodules.empty? && unlisted_submodules.empty?, message
+    assert nonexistent_submodules.empty? && unlisted_submodules.empty?, message.sub(/\.\Z/, "")
   end
 
   def test_local_scopes_are_in_sync
@@ -106,18 +106,24 @@ class TestGrammars < Minitest::Test
     end
   end
 
+  def test_readme_file_is_in_sync
+    current_data = File.read("#{ROOT}/vendor/README.md").to_s.sub(/\A.+?<!--.+?-->\n/ms, "")
+    updated_data = `script/list-grammars --print`
+    assert_equal current_data, updated_data, "Grammar list is out-of-date. Run `script/list-grammars`"
+  end
+
   def test_submodules_have_recognized_licenses
     unrecognized = submodule_licenses.select { |k,v| v.nil? && Licensee::FSProject.new(k).license_file }
     unrecognized.reject! { |k,v| PROJECT_WHITELIST.include?(k) }
     message = "The following submodules have unrecognized licenses:\n* #{unrecognized.keys.join("\n* ")}\n"
-    message << "Please ensure that the project's LICENSE file contains the full text of the license."
+    message << "Please ensure that the project's LICENSE file contains the full text of the license"
     assert_equal Hash.new, unrecognized, message
   end
 
   def test_submodules_have_licenses
     unlicensed = submodule_licenses.select { |k,v| v.nil? }.reject { |k,v| PROJECT_WHITELIST.include?(k) }
     message = "The following submodules don't have licenses:\n* #{unlicensed.keys.join("\n* ")}\n"
-    message << "Please ensure that the project has a LICENSE file, and that the LICENSE file contains the full text of the license."
+    message << "Please ensure that the project has a LICENSE file, and that the LICENSE file contains the full text of the license"
     assert_equal Hash.new, unlicensed, message
   end
 
@@ -127,14 +133,14 @@ class TestGrammars < Minitest::Test
                                                    HASH_WHITELIST.include?(v) }
                                    .map { |k,v| "#{k}: #{v}"}
     message = "The following submodules have unapproved licenses:\n* #{unapproved.join("\n* ")}\n"
-    message << "The license must be added to the LICENSE_WHITELIST in /test/test_grammars.rb once approved."
+    message << "The license must be added to the LICENSE_WHITELIST in /test/test_grammars.rb once approved"
     assert_equal [], unapproved, message
   end
 
   def test_whitelisted_submodules_dont_have_licenses
     licensed = submodule_licenses.reject { |k,v| v.nil? }.select { |k,v| PROJECT_WHITELIST.include?(k) }
     message = "The following whitelisted submodules have a license:\n* #{licensed.keys.join("\n* ")}\n"
-    message << "Please remove them from the project whitelist."
+    message << "Please remove them from the project whitelist"
     assert_equal Hash.new, licensed, message
   end
 
@@ -142,7 +148,7 @@ class TestGrammars < Minitest::Test
     used_hashes = submodule_licenses.values.reject { |v| v.nil? || LICENSE_WHITELIST.include?(v) }
     unused_hashes = HASH_WHITELIST - used_hashes
     message = "The following whitelisted license hashes are unused:\n* #{unused_hashes.join("\n* ")}\n"
-    message << "Please remove them from the hash whitelist."
+    message << "Please remove them from the hash whitelist"
     assert_equal Array.new, unused_hashes, message
   end
 
diff --git a/vendor/README.md b/vendor/README.md
index 36108711..cd6373fb 100644
--- a/vendor/README.md
+++ b/vendor/README.md
@@ -9,6 +9,7 @@ This is a list of grammars that Linguist selects to provide syntax highlighting
 - **ABNF:** [sanssecours/ABNF.tmbundle](https://github.com/sanssecours/ABNF.tmbundle)
 - **ActionScript:** [simongregory/actionscript3-tmbundle](https://github.com/simongregory/actionscript3-tmbundle)
 - **Ada:** [textmate/ada.tmbundle](https://github.com/textmate/ada.tmbundle)
+- **Adobe Font Metrics:** [Alhadis/language-fontforge](https://github.com/Alhadis/language-fontforge)
 - **Agda:** [mokus0/Agda.tmbundle](https://github.com/mokus0/Agda.tmbundle)
 - **AGS Script:** [textmate/c.tmbundle](https://github.com/textmate/c.tmbundle)
 - **Alloy:** [macekond/Alloy.tmbundle](https://github.com/macekond/Alloy.tmbundle)
@@ -123,6 +124,7 @@ This is a list of grammars that Linguist selects to provide syntax highlighting
 - **Genshi:** [genshi.edgewall.org/query](https://genshi.edgewall.org/query)
 - **Gentoo Ebuild:** [atom/language-shellscript](https://github.com/atom/language-shellscript)
 - **Gentoo Eclass:** [atom/language-shellscript](https://github.com/atom/language-shellscript)
+- **Gerber Image:** [Alhadis/language-pcb](https://github.com/Alhadis/language-pcb)
 - **Gettext Catalog:** [textmate/gettext.tmbundle](https://github.com/textmate/gettext.tmbundle)
 - **Gherkin:** [cucumber/cucumber-tmbundle](https://github.com/cucumber/cucumber-tmbundle)
 - **GLSL:** [euler0/sublime-glsl](https://github.com/euler0/sublime-glsl)
@@ -225,6 +227,7 @@ This is a list of grammars that Linguist selects to provide syntax highlighting
 - **MTML:** [textmate/html.tmbundle](https://github.com/textmate/html.tmbundle)
 - **mupad:** [ccreutzig/sublime-MuPAD](https://github.com/ccreutzig/sublime-MuPAD)
 - **NCL:** [rpavlick/language-ncl](https://github.com/rpavlick/language-ncl)
+- **Nearley:** [Hardmath123/sublime-nearley](https://github.com/Hardmath123/sublime-nearley)
 - **Nemerle:** [textmate/nemerle.tmbundle](https://github.com/textmate/nemerle.tmbundle)
 - **nesC:** [cdwilson/nesC.tmbundle](https://github.com/cdwilson/nesC.tmbundle)
 - **NetLinx:** [amclain/sublime-netlinx](https://github.com/amclain/sublime-netlinx)
@@ -387,6 +390,7 @@ This is a list of grammars that Linguist selects to provide syntax highlighting
 - **XCompose:** [samcv/language-xcompose](https://github.com/samcv/language-xcompose)
 - **XML:** [textmate/xml.tmbundle](https://github.com/textmate/xml.tmbundle)
 - **Xojo:** [angryant0007/VBDotNetSyntax](https://github.com/angryant0007/VBDotNetSyntax)
+- **XPages:** [textmate/xml.tmbundle](https://github.com/textmate/xml.tmbundle)
 - **XPM:** [textmate/c.tmbundle](https://github.com/textmate/c.tmbundle)
 - **XProc:** [textmate/xml.tmbundle](https://github.com/textmate/xml.tmbundle)
 - **XQuery:** [wcandillon/language-jsoniq](https://github.com/wcandillon/language-jsoniq)