diff --git a/gengo/languages.yaml b/gengo/languages.yaml
index d5d45a01..27131f45 100644
--- a/gengo/languages.yaml
+++ b/gengo/languages.yaml
@@ -47,6 +47,14 @@
 #
 # WARNING: Please alphabetize!
 ---
+"C#":
+  category: programming
+  color: "#178600"
+  heuristics:
+    - "^\\s*(using\\s+[A-Z][\\s\\w.]+;|namespace\\s*[\\w\\.]+\\s*(\\{|;)|\\/\\/)"
+  matchers:
+    extensions:
+      - cs
 CoffeeScript:
   category: programming
   color: "#3E2723"
diff --git a/scripts/check-languages-file.rb b/scripts/check-languages-file.rb
index 7b021269..f9fdaf30 100755
--- a/scripts/check-languages-file.rb
+++ b/scripts/check-languages-file.rb
@@ -37,13 +37,13 @@ def sorted?(array)
   end
   next if missing_required
 
-  if langdef.key?('heuristics') && !langdef['hueristics'].is_a?(Array)
-    STDERR.puts "#{langname}: 'hueristics' must be an array"
+  if langdef.key?('heuristics') && !langdef['heuristics'].is_a?(Array)
+    STDERR.puts "#{langname}: 'heuristics' must be an array"
     exit_code = 1
   end
-  hueristics = langdef['hueristics'] || []
-  sorted?(hueristics) do |a, b|
-    STDERR.puts "#{langname}: 'hueristics' are out of order: '#{a}' and '#{b}'"
+  heuristics = langdef['heuristics'] || []
+  sorted?(heuristics) do |a, b|
+    STDERR.puts "#{langname}: 'heuristics' are out of order: '#{a}' and '#{b}'"
     exit_code = 1
   end