diff --git a/atomic_red_team/atomic_red_team.rb b/atomic_red_team/atomic_red_team.rb
index bad5c204..57546cc6 100755
--- a/atomic_red_team/atomic_red_team.rb
+++ b/atomic_red_team/atomic_red_team.rb
@@ -152,13 +152,35 @@ class AtomicRedTeam
     end
   end
 
-  def generate_guids_for_yaml!(path)
-    guids = []
+  def generate_guids_for_yaml!(path, used_guids_file)
     text = File.read(path) 
-    content = text.gsub(/(?i)^\s*guid:(?!(\s*[a-f0-9]{8}-[a-f0-9]{4}-4[a-f0-9]{3}-[89aAbB][a-f0-9]{3}-[a-f0-9]{12})).*$/) { |m| "auto_generated_guid: #{SecureRandom.uuid}"} 
+    guid = get_unique_guid(used_guids_file)
+    # add the "auto_generated_guid:" element after the "- name:" element if it isn't already there
+    c = text.gsub(/(?i)(^(\s*-\s*)name:.*$(?!\s*auto_generated_guid))/) { |m| "#{$1}\n  auto_generated_guid:"}
+    # fill the "auto_generated_guid:" element in if it doesn't contain a guid
+    content = c.gsub(/(?i)^(\s*auto_generated_guid:)(?!(\s*[a-f0-9]{8}-[a-f0-9]{4}-4[a-f0-9]{3}-[89aAbB][a-f0-9]{3}-[a-f0-9]{12})).*$/) { |m| "#{$1} #{get_unique_guid(used_guids_file)}"}
+
     File.open(path, "w") { |file| file << content }
   end
 
+  def get_unique_guid(used_guids_file)
+    new_guid = ''
+    20.times do |i| # if it takes more than 20 tries to get a unique guid, there must be something else going on
+      new_guid = SecureRandom.uuid
+      break unless !is_unique_guid(new_guid, used_guids_file)
+    end
+    # add this new unique guid to the used guids file
+    open(used_guids_file, 'a') { |f|
+      puts used_guids_file
+      f.puts new_guid unless new_guid == ''
+    }
+    return new_guid
+  end
+
+  def is_unique_guid(guid, used_guids_file)
+    return !File.foreach(used_guids_file).grep(/#{guid}/).any?
+  end
+
   #
   # Validates that the arguments (specified in "#{arg}" format) in a string
   # match the input_arguments for a test
diff --git a/atomic_red_team/spec.yaml b/atomic_red_team/spec.yaml
index e7bfe631..80bf8f6b 100644
--- a/atomic_red_team/spec.yaml
+++ b/atomic_red_team/spec.yaml
@@ -35,7 +35,7 @@ atomic_tests:
 # This is the first atomic test
 #
 - name: Short name of the test that titles how it tests the technique. # Example: "SourceRecorder via cmd.exe"
-  auto_generated_guid: # uniquely identifies this test, leave it blank and it will be auto-generated during the Pull Request process on GitHub
+  auto_generated_guid: # This key and/or it's value will be added by the CI build after submitting a Pull Request
   description: |
     Long form description of the test. Markdown is supported so you can **bold** items, create
 
diff --git a/bin/generate-guids.rb b/bin/generate-guids.rb
index 368e2afc..53c8dcd0 100644
--- a/bin/generate-guids.rb
+++ b/bin/generate-guids.rb
@@ -4,16 +4,16 @@ require 'yaml'
 require 'atomic_red_team'
 
 ATOMIC_RED_TEAM = AtomicRedTeam.new
-ATOMIC_TEST_TEMPLATE = "#{File.dirname(File.dirname(__FILE__))}/atomic_red_team/atomic_test_template.yaml"
+USED_GUIDS_FILE = "#{File.dirname(File.dirname(__FILE__))}/atomic_red_team/used_guids.txt"
 
 oks = []
 fails = []
 
 ATOMIC_RED_TEAM.atomic_test_paths.each do |path|
   begin
-    print "Validating #{path}..."
+    print "Generating guids #{path}..."
     YAML.load_file(path)
-    AtomicRedTeam.new.generate_guids_for_yaml! path
+    AtomicRedTeam.new.generate_guids_for_yaml!(path, USED_GUIDS_FILE)
 
     oks << path
     puts "OK"