diff --git a/lib/linguist/mime.rb b/lib/linguist/mime.rb
index e280209f..59f30ada 100644
--- a/lib/linguist/mime.rb
+++ b/lib/linguist/mime.rb
@@ -1,49 +1,6 @@
 require 'mime/types'
 require 'yaml'
 
-class MIME::Type
-  attr_accessor :override
-end
-
-# Register additional mime type extensions
-#
-# Follows same format as mime-types data file
-#   https://github.com/halostatue/mime-types/blob/master/lib/mime/types.rb.data
-File.read(File.expand_path("../mimes.yml", __FILE__)).lines.each do |line|
-  # Regexp was cargo culted from mime-types lib
-  next unless line =~ %r{^
-    #{MIME::Type::MEDIA_TYPE_RE}
-    (?:\s@([^\s]+))?
-    (?:\s:(#{MIME::Type::ENCODING_RE}))?
-  }x
-
-  mediatype  = $1
-  subtype    = $2
-  extensions = $3
-  encoding   = $4
-
-  # Lookup existing mime type
-  mime_type = MIME::Types["#{mediatype}/#{subtype}"].first ||
-    # Or create a new instance
-    MIME::Type.new("#{mediatype}/#{subtype}")
-
-  if extensions
-    extensions.split(/,/).each do |extension|
-      mime_type.extensions << extension
-    end
-  end
-
-  if encoding
-    mime_type.encoding = encoding
-  end
-
-  mime_type.override = true
-
-  # Kind of hacky, but we need to reindex the mime type after making changes
-  MIME::Types.add_type_variant(mime_type)
-  MIME::Types.index_extensions(mime_type)
-end
-
 module Linguist
   module Mime
     # Internal: Look up mime type for extension.
@@ -78,11 +35,8 @@ module Linguist
         guesses = ::MIME::Types.type_for(ext_or_mime_type)
       end
 
-      # Use custom override first
-      guesses.detect { |type| type.override } ||
-
-        # Prefer text mime types over binary
-        guesses.detect { |type| type.ascii? } ||
+      # Prefer text mime types over binary
+      guesses.detect { |type| type.ascii? } ||
 
         # Otherwise use the first guess
         guesses.first
diff --git a/lib/linguist/mimes.yml b/lib/linguist/mimes.yml
deleted file mode 100644
index a410f4b2..00000000
--- a/lib/linguist/mimes.yml
+++ /dev/null
@@ -1,38 +0,0 @@
-# Additional types to add to MIME::Types
-#
-# MIME types are used to set the Content-Type of raw binary blobs. All text
-# blobs are served as text/plain regardless of their type to ensure they
-# open in the browser rather than downloading.
-#
-# The encoding helps determine whether a file should be treated as plain
-# text or binary. By default, a mime type's encoding is base64 (binary).
-# These types will show a "View Raw" link. To force a type to render as
-# plain text, set it to 8bit for UTF-8. text/* types will be treated as
-# text by default.
-#
-#   <type> @<extensions> :<encoding>
-#
-# type       - mediatype/subtype
-# extensions - comma seperated extension list
-# encoding   - base64 (binary), 7bit (ASCII), 8bit (UTF-8), or
-#              quoted-printable (Printable ASCII).
-#
-# Follows same format as mime-types data file
-#   https://github.com/halostatue/mime-types/blob/master/lib/mime/types.rb.data
-#
-# Any additions or modifications (even trivial) should have corresponding
-# test change in `test/test_mime.rb`.
-
-# Please keep this list alphabetized
-application/java-archive @ear,war
-application/octet-stream @o
-application/x-chrome-extension @crx
-application/x-supercollider @sc :8bit
-application/xslt+xml @xslt :8bit
-image/x-icns @icns
-text/cache-manifest @manifest
-text/plain @cu,cxx
-text/x-logtalk @lgt
-text/x-nimrod @nim
-text/x-ocaml @ml,mli,mll,mly,sig,sml
-text/x-scheme @rkt,scm,sls,sps,ss
diff --git a/test/test_blob.rb b/test/test_blob.rb
index 8dcce3d9..0832b8fd 100644
--- a/test/test_blob.rb
+++ b/test/test_blob.rb
@@ -30,7 +30,6 @@ class TestBlob < Test::Unit::TestCase
   end
 
   def test_mime_type
-    assert_equal "application/octet-stream", blob("Binary/dog.o").mime_type
     assert_equal "application/postscript", blob("Binary/octocat.ai").mime_type
     assert_equal "application/x-ruby", blob("Ruby/grit.rb").mime_type
     assert_equal "application/x-sh", blob("Shell/script.sh").mime_type
@@ -40,7 +39,6 @@ class TestBlob < Test::Unit::TestCase
   end
 
   def test_content_type
-    assert_equal "application/octet-stream", blob("Binary/dog.o").content_type
     assert_equal "application/pdf", blob("Binary/foo.pdf").content_type
     assert_equal "audio/ogg", blob("Binary/foo.ogg").content_type
     assert_equal "image/png", blob("Binary/foo.png").content_type
diff --git a/test/test_mime.rb b/test/test_mime.rb
index 8c0f1d1d..81c212ec 100644
--- a/test/test_mime.rb
+++ b/test/test_mime.rb
@@ -26,11 +26,7 @@ class TestMime < Test::Unit::TestCase
     assert_equal 'application/vnd.oasis.opendocument.spreadsheet', Mime.mime_for('.ods')
     assert_equal 'application/vnd.oasis.opendocument.text', Mime.mime_for('.odt')
     assert_equal 'application/vnd.openxmlformats-officedocument.presentationml.presentation', Mime.mime_for('.pptx')
-    assert_equal 'application/x-chrome-extension', Mime.mime_for('.crx')
     assert_equal 'application/x-debian-package', Mime.mime_for('.deb')
-    assert_equal 'application/x-java-archive', Mime.mime_for('.ear')
-    assert_equal 'application/x-java-archive', Mime.mime_for('.jar')
-    assert_equal 'application/x-java-archive', Mime.mime_for('.war')
     assert_equal 'application/x-latex', Mime.mime_for('.latex')
     assert_equal 'application/x-perl', Mime.mime_for('.pl')
     assert_equal 'application/x-perl', Mime.mime_for('.pm')
@@ -38,23 +34,15 @@ class TestMime < Test::Unit::TestCase
     assert_equal 'application/x-ruby', Mime.mime_for('.rb')
     assert_equal 'application/x-sh', Mime.mime_for('.sh')
     assert_equal 'application/x-shockwave-flash', Mime.mime_for('.swf')
-    assert_equal 'application/x-supercollider', Mime.mime_for('.sc')
-    assert_equal 'text/cache-manifest', Mime.mime_for('.manifest')
     assert_equal 'text/html', Mime.mime_for('.html')
     assert_equal 'text/plain', Mime.mime_for('.c')
     assert_equal 'text/plain', Mime.mime_for('.cc')
     assert_equal 'text/plain', Mime.mime_for('.cpp')
-    assert_equal 'text/plain', Mime.mime_for('.cu')
     assert_equal 'text/plain', Mime.mime_for('.cxx')
     assert_equal 'text/plain', Mime.mime_for('.h')
     assert_equal 'text/plain', Mime.mime_for('.hh')
     assert_equal 'text/plain', Mime.mime_for('.hpp')
     assert_equal 'text/plain', Mime.mime_for('.kt')
-    assert_equal 'text/x-logtalk', Mime.mime_for('.lgt')
-    assert_equal 'text/x-nimrod', Mime.mime_for('.nim')
-    assert_equal 'text/x-ocaml', Mime.mime_for('.ml')
-    assert_equal 'text/x-ocaml', Mime.mime_for('.sig')
-    assert_equal 'text/x-ocaml', Mime.mime_for('.sml')
     assert_equal 'video/quicktime', Mime.mime_for('.mov')
   end
 end