diff --git a/lib/linguist/languages.yml b/lib/linguist/languages.yml
index d2cc8655..1a04727b 100644
--- a/lib/linguist/languages.yml
+++ b/lib/linguist/languages.yml
@@ -637,6 +637,14 @@ Smarty:
   extensions:
   - .tpl
 
+Standard ML:
+  lexer: OCaml
+  aliases:
+  - sml
+  extensions:
+  - .sig
+  - .sml
+
 SuperCollider:
   lexer: Text only
   extensions:
diff --git a/lib/linguist/mimes.yml b/lib/linguist/mimes.yml
index 5c476045..06a80991 100644
--- a/lib/linguist/mimes.yml
+++ b/lib/linguist/mimes.yml
@@ -50,3 +50,4 @@ image/x-icns @icns
 text/cache-manifest @manifest
 text/plain @cu,cxx
 text/x-nimrod @nim
+text/x-ocaml @ml,mli,mll,mly,sig,sml
diff --git a/test/test_blob.rb b/test/test_blob.rb
index 3bd25e93..a573e79f 100644
--- a/test/test_blob.rb
+++ b/test/test_blob.rb
@@ -224,6 +224,11 @@ class TestBlob < Test::Unit::TestCase
     assert_equal Language['Ruby'],        blob("wrong_shebang.rb").language
     assert_equal Language['Text'],        blob("octocat.png").language
 
+    # ML
+    assert_equal Language['OCaml'],       blob("Foo.ml").language
+    assert_equal Language['Standard ML'], blob("Foo.sig").language
+    assert_equal Language['Standard ML'], blob("Foo.sml").language
+
     # Config files
     assert_equal Language['INI'],   blob(".gitconfig").language
     assert_equal Language['Shell'], blob(".bash_profile").language
diff --git a/test/test_language.rb b/test/test_language.rb
index c31c73af..f83676af 100644
--- a/test/test_language.rb
+++ b/test/test_language.rb
@@ -73,6 +73,7 @@ class TestLanguage < Test::Unit::TestCase
     assert_equal Lexer['NumPy'], Language['NumPy'].lexer
     assert_equal Lexer['OCaml'], Language['F#'].lexer
     assert_equal Lexer['OCaml'], Language['OCaml'].lexer
+    assert_equal Lexer['OCaml'], Language['Standard ML'].lexer
     assert_equal Lexer['Objective-C'], Language['Objective-C'].lexer
     assert_equal Lexer['Objective-J'], Language['Objective-J'].lexer
     assert_equal Lexer['Ooc'], Language['ooc'].lexer
diff --git a/test/test_mime.rb b/test/test_mime.rb
index 3bc4c626..6efb22f7 100644
--- a/test/test_mime.rb
+++ b/test/test_mime.rb
@@ -46,6 +46,9 @@ class TestMime < Test::Unit::TestCase
     assert_equal 'text/cache-manifest', Mime.mime_for('.manifest')
     assert_equal 'text/html', Mime.mime_for('.html')
     assert_equal 'text/nimrod', Mime.mime_for('.nim')
+    assert_equal 'text/ocaml', Mime.mime_for('.ml')
+    assert_equal 'text/ocaml', Mime.mime_for('.sig')
+    assert_equal 'text/ocaml', Mime.mime_for('.sml')
     assert_equal 'text/plain', Mime.mime_for('.c')
     assert_equal 'text/plain', Mime.mime_for('.cc')
     assert_equal 'text/plain', Mime.mime_for('.cpp')
@@ -160,6 +163,8 @@ class TestMime < Test::Unit::TestCase
     assert Mime.text?('.rb')
     assert Mime.text?('.sc')
     assert Mime.text?('.sh')
+    assert Mime.text?('.sig')
+    assert Mime.text?('.sml')
     assert Mime.text?('.src')
     assert Mime.text?('.tcl')
     assert Mime.text?('.texi')