diff --git a/lib/fizzbuzz.rb b/lib/fizzbuzz.rb
index 4746a88..f09ba07 100644
--- a/lib/fizzbuzz.rb
+++ b/lib/fizzbuzz.rb
@@ -1,13 +1,15 @@
 class Fizzbuzz
   def calculate number
     if number % 3 == 0 && number % 5 == 0
-      'fizzbuzz'
+        'fizzbuzz'
     elsif number % 3 == 0
-      'fizz'
+        'fizz'
     elsif number % 5 == 0
-      'buzz'
+        'buzz'
+    elsif number.to_s.include?'7'
+        'GitHub'
     else
-      number
+        number
     end
   end
 end
diff --git a/spec/fizzbuzz_spec.rb b/spec/fizzbuzz_spec.rb
index 93a63e6..7f4b864 100644
--- a/spec/fizzbuzz_spec.rb
+++ b/spec/fizzbuzz_spec.rb
@@ -20,4 +20,10 @@
     it { subject.calculate(15).should eq 'fizzbuzz' }
     it { subject.calculate(30).should eq 'fizzbuzz' }
   end
+  context 'GitHub number' do
+    it { subject.calculate(17).should eq 'GitHub'}
+    it { subject.calculate(27).should eq 'GitHub'}
+    it { subject.calculate(75).should eq 'GitHub'}
+    it { subject.calculate(77).should eq 'GitHub'}
+  end
 end