diff --git a/lib/linguist.rb b/lib/linguist.rb
index 0f1b0f83..e717fb67 100644
--- a/lib/linguist.rb
+++ b/lib/linguist.rb
@@ -1,6 +1,5 @@
 require 'linguist/blob_helper'
 require 'linguist/generated'
 require 'linguist/language'
-require 'linguist/mime'
 require 'linguist/repository'
 require 'linguist/samples'
diff --git a/lib/linguist/blob_helper.rb b/lib/linguist/blob_helper.rb
index 75bee673..b2d72f11 100644
--- a/lib/linguist/blob_helper.rb
+++ b/lib/linguist/blob_helper.rb
@@ -1,9 +1,9 @@
 require 'linguist/generated'
 require 'linguist/language'
-require 'linguist/mime'
 
 require 'charlock_holmes'
 require 'escape_utils'
+require 'mime/types'
 require 'pygments'
 require 'yaml'
 
@@ -23,6 +23,22 @@ module Linguist
       File.extname(name.to_s)
     end
 
+    # Internal: Lookup mime type for extension.
+    #
+    # Returns a MIME::Type
+    def _mime_type
+      if defined? @_mime_type
+        @_mime_type
+      else
+        guesses = ::MIME::Types.type_for(extname.to_s)
+
+        # Prefer text mime types over binary
+        @_mime_type = guesses.detect { |type| type.ascii? } ||
+          # Otherwise use the first guess
+          guesses.first
+      end
+    end
+
     # Public: Get the actual blob mime type
     #
     # Examples
@@ -32,10 +48,14 @@ module Linguist
     #
     # Returns a mime type String.
     def mime_type
-      @mime_type ||= begin
-        mime_type = Mime.lookup_mime_type_for(extname.to_s)
-        mime_type ? mime_type.to_s : 'text/plain'
-      end
+      _mime_type ? _mime_type.to_s : 'text/plain'
+    end
+
+    # Internal: Is the blob binary according to its mime type
+    #
+    # Return true or false
+    def binary_mime_type?
+      _mime_type ? _mime_type.binary? : false
     end
 
     # Public: Get the Content-Type header value
@@ -86,15 +106,6 @@ module Linguist
       @detect_encoding ||= CharlockHolmes::EncodingDetector.new.detect(data) if data
     end
 
-    # Internal: Is the blob binary according to its mime type
-    #
-    # Return true or false
-    def binary_mime_type?
-      if mime_type = Mime.lookup_mime_type_for(extname)
-        mime_type.binary?
-      end
-    end
-
     # Public: Is the blob binary?
     #
     # Return true or false
diff --git a/lib/linguist/mime.rb b/lib/linguist/mime.rb
deleted file mode 100644
index a1e5555f..00000000
--- a/lib/linguist/mime.rb
+++ /dev/null
@@ -1,27 +0,0 @@
-require 'mime/types'
-require 'yaml'
-
-module Linguist
-  module Mime
-    # Internal: Lookup mime type for extension or mime type
-    #
-    # ext_or_mime_type - A file extension ".txt" or mime type "text/plain".
-    #
-    # Returns a MIME::Type
-    def self.lookup_mime_type_for(ext_or_mime_type)
-      ext_or_mime_type ||= ''
-
-      if ext_or_mime_type =~ /\w+\/\w+/
-        guesses = ::MIME::Types[ext_or_mime_type]
-      else
-        guesses = ::MIME::Types.type_for(ext_or_mime_type)
-      end
-
-      # Prefer text mime types over binary
-      guesses.detect { |type| type.ascii? } ||
-
-        # Otherwise use the first guess
-        guesses.first
-    end
-  end
-end