diff --git a/lib/linguist/heuristics.rb b/lib/linguist/heuristics.rb
index 4c1bf295..11a6a10d 100644
--- a/lib/linguist/heuristics.rb
+++ b/lib/linguist/heuristics.rb
@@ -25,6 +25,9 @@ module Linguist
         if languages.all? { |l| ["Common Lisp", "OpenCL"].include?(l) }
           result = disambiguate_cl(data, languages)
         end
+        if languages.all? { |l| ["AsciiDoc", "AGS Script"].include?(l) }
+          result = disambiguate_asc(data, languages)
+        end
         return result
       end
     end
@@ -88,6 +91,12 @@ module Linguist
       matches
     end
 
+    def self.disambiguate_asc(data, languages)
+      matches = []
+      matches << Language["AsciiDoc"] if /^=+(\s|\n)/.match(data)
+      matches
+    end
+
     def self.active?
       !!ACTIVE
     end
diff --git a/test/test_heuristics.rb b/test/test_heuristics.rb
index 55fb5331..80a0007a 100644
--- a/test/test_heuristics.rb
+++ b/test/test_heuristics.rb
@@ -77,6 +77,12 @@ class TestHeuristcs < Test::Unit::TestCase
     assert_equal Language["IDL"], results.first
   end
 
+  def test_asc_asciidoc_by_heuristics
+    languages = ["AGS Script", "AsciiDoc"]
+    results = Heuristics.disambiguate_asc(fixture("AsciiDoc/list.asc"), languages)
+    assert_equal Language["AsciiDoc"], results.first
+  end
+
   def test_ts_typescript_by_heuristics
     languages = ["TypeScript", "XML"]
     results = Heuristics.disambiguate_ts(fixture("TypeScript/classes.ts"), languages)