diff --git a/lib/linguist/heuristics.rb b/lib/linguist/heuristics.rb
index 8585dbfe..c7519881 100644
--- a/lib/linguist/heuristics.rb
+++ b/lib/linguist/heuristics.rb
@@ -34,9 +34,6 @@ module Linguist
         if languages.all? { |l| ["AsciiDoc", "AGS Script"].include?(l) }
           result = disambiguate_asc(data, languages)
         end
-        if languages.all? { |l| ["XML", "Objective-C++"].include?(l) }
-          result = disambiguate_mm(data, languages)
-        end
         return result
       end
     end
@@ -127,16 +124,6 @@ module Linguist
       matches
     end
 
-    def self.disambiguate_mm(data, languages)
-      matches = []
-      if /<map version="[^"]+">/.match(data)
-        matches << Language["XML"]
-      else
-        matches << Language["Objective-C++"]
-      end
-      matches
-    end
-
     def self.active?
       !!ACTIVE
     end
diff --git a/test/test_heuristics.rb b/test/test_heuristics.rb
index 7f9fc585..e75fb470 100644
--- a/test/test_heuristics.rb
+++ b/test/test_heuristics.rb
@@ -122,16 +122,4 @@ class TestHeuristcs < Test::Unit::TestCase
     results = Heuristics.disambiguate_sc(fixture("Scala/node11.sc"), languages)
     assert_equal Language["Scala"], results.first
   end
-
-  def test_mm_objective_cpp_by_heuristics
-    languages = ["XML", "Objective-C++"]
-    results = Heuristics.disambiguate_mm(fixture("Objective-C++/objsql.mm"), languages)
-    assert_equal Language["Objective-C++"], results.first
-  end
-
-  def test_mm_xml_by_heuristics
-    languages = ["XML", "Objective-C++"]
-    results = Heuristics.disambiguate_mm(fixture("XML/some-ideas.mm"), languages)
-    assert_equal Language["XML"], results.first
-  end
 end