diff --git a/atomic_red_team/atomic_red_team.rb b/atomic_red_team/atomic_red_team.rb
index c0ae26c1..e282a021 100755
--- a/atomic_red_team/atomic_red_team.rb
+++ b/atomic_red_team/atomic_red_team.rb
@@ -62,7 +62,7 @@ class AtomicRedTeam
     end
   end
 
-  def validate_atomic_yaml!(yaml, used_guids_file)
+  def validate_atomic_yaml!(yaml, used_guids_file, unique_guid_array)
     raise("YAML file has no elements") if yaml.nil?
   
     raise('`attack_technique` element is required') unless yaml.has_key?('attack_technique')
@@ -81,8 +81,10 @@ class AtomicRedTeam
 
       if atomic.has_key?('auto_generated_guid')
         guid = atomic["auto_generated_guid"].to_s
-        raise("`atomic_tests[#{i}].auto_generated_guid` element must be unique") unless is_unique_guid(guid, used_guids_file)
         raise("`atomic_tests[#{i}].auto_generated_guid` element not a proper guid") unless /[a-f0-9]{8}-[a-f0-9]{4}-4[a-f0-9]{3}-[89aAbB][a-f0-9]{3}-[a-f0-9]{12}/.match(guid)
+        raise("`atomic_tests[#{i}].auto_generated_guid` element must be unique") unless !unique_guid_array.include?(guid)
+        unique_guid_array << guid
+        add_guid_to_used_guid_file(guid, used_guids_file)
       end
 
       raise("`atomic_tests[#{i}].description` element is required") unless atomic.has_key?('description')
@@ -150,30 +152,46 @@ class AtomicRedTeam
     end
   end
 
+  def record_used_guids!(yaml, used_guids_file)
+    return unless !yaml.nil?
+ 
+    yaml['atomic_tests'].each_with_index do |atomic, i|
+      next unless atomic.has_key?('auto_generated_guid')
+      guid = atomic["auto_generated_guid"].to_s
+      add_guid_to_used_guid_file(guid, used_guids_file)
+    end
+  end
+
   def generate_guids_for_yaml!(path, used_guids_file)
     text = File.read(path) 
-    guid = get_unique_guid(used_guids_file)
     # add the "auto_generated_guid:" element after the "- name:" element if it isn't already there
     text.gsub!(/(?i)(^([ \t]*-[ \t]*)name:.*$(?!\s*auto_generated_guid))/) { |m| "#{$1}\n#{$2.gsub(/-/," ")}auto_generated_guid:"}
     # fill the "auto_generated_guid:" element in if it doesn't contain a guid
-    text.gsub!(/(?i)^([ \t]*auto_generated_guid:)(?!([ \t]*[a-f0-9]{8}-[a-f0-9]{4}-4[a-f0-9]{3}-[89aAbB][a-f0-9]{3}-[a-f0-9]{12})).*$/) { |m| "#{$1} #{get_unique_guid(used_guids_file)}"}
+    text.gsub!(/(?i)^([ \t]*auto_generated_guid:)(?!([ \t]*[a-f0-9]{8}-[a-f0-9]{4}-4[a-f0-9]{3}-[89aAbB][a-f0-9]{3}-[a-f0-9]{12})).*$/) { |m| "#{$1} #{get_unique_guid!(used_guids_file)}"}
 
     File.open(path, "w") { |file| file << text }
   end
 
-  def get_unique_guid(used_guids_file)
+  # generates a unique guid and records the guid as having been used by writing it to the used_guids_file
+  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|
-      f.puts new_guid unless new_guid == ''
-    }
+    add_guid_to_used_guid_file(new_guid, used_guids_file) 
     return new_guid
   end
 
+  # add guid to used guid file if it is the proper format and is not already in the file. raises an exception if guid isn't valid
+  def add_guid_to_used_guid_file(guid, used_guids_file)
+    open(used_guids_file, 'a') { |f|
+      raise("`atomic_tests[#{i}].executor.command` element is required") unless /[a-f0-9]{8}-[a-f0-9]{4}-4[a-f0-9]{3}-[89aAbB][a-f0-9]{3}-[a-f0-9]{12}/ =~ guid
+      f.puts guid unless !is_unique_guid(guid, used_guids_file)
+    }
+  end
+
   def is_unique_guid(guid, used_guids_file)
     return !File.foreach(used_guids_file).grep(/#{guid}/).any?
   end
diff --git a/bin/generate-guids.rb b/bin/generate-guids.rb
index 74b76571..bceb7c44 100755
--- a/bin/generate-guids.rb
+++ b/bin/generate-guids.rb
@@ -12,7 +12,8 @@ fails = []
 ATOMIC_RED_TEAM.atomic_test_paths.each do |path|
   begin
     print "Generating guids #{path}..."
-    YAML.load_file(path)
+    
+    ATOMIC_RED_TEAM.record_used_guids!(YAML.load_file(path), USED_GUIDS_FILE)
     AtomicRedTeam.new.generate_guids_for_yaml!(path, USED_GUIDS_FILE)
 
     oks << path
diff --git a/bin/validate-atomics.rb b/bin/validate-atomics.rb
index 1f229087..4c1b78f7 100755
--- a/bin/validate-atomics.rb
+++ b/bin/validate-atomics.rb
@@ -9,12 +9,12 @@ USED_GUIDS_FILE = "#{File.dirname(File.dirname(__FILE__))}/atomics/used_guids.tx
 
 oks = []
 fails = []
+unique_guid_array = []
 
 ATOMIC_RED_TEAM.atomic_test_paths.each do |path|
   begin
     print "Validating #{path}..."
-    YAML.load_file(path)
-    AtomicRedTeam.new.validate_atomic_yaml!(YAML.load_file(path), USED_GUIDS_FILE)
+    AtomicRedTeam.new.validate_atomic_yaml!(YAML.load_file(path), USED_GUIDS_FILE, unique_guid_array)
 
     oks << path
     puts "OK"