diff --git a/lib/puppet/type/sshkey.rb b/lib/puppet/type/sshkey.rb
index 11d6cef..7971d62 100644
--- a/lib/puppet/type/sshkey.rb
+++ b/lib/puppet/type/sshkey.rb
@@ -85,7 +85,7 @@ def should
         if %r{\s}.match?(value)
           raise Puppet::Error, _('Aliases cannot include whitespace')
         end
-        if %r{,}.match?(value)
+        if value.include?(',')
           raise Puppet::Error, _('Aliases must be provided as an array, not a comma-separated list')
         end
       end
diff --git a/spec/acceptance/tests/resource/ssh_authorized_key/create_spec.rb b/spec/acceptance/tests/resource/ssh_authorized_key/create_spec.rb
index d19d328..5a9f53d 100644
--- a/spec/acceptance/tests/resource/ssh_authorized_key/create_spec.rb
+++ b/spec/acceptance/tests/resource/ssh_authorized_key/create_spec.rb
@@ -65,7 +65,7 @@
               'drop_privileges=false',
               "target=/home/testuser/tmp/ssh_authorized_keys_#{name}/authorized_keys_#{name}"]
       on(agent, puppet_resource('ssh_authorized_key', name.to_s, args)) do |_res|
-        fail_test unless %r{the target path is not trusted}.match?(stderr)
+        fail_test unless stderr.include?('the target path is not trusted')
       end
       on(agent, "rm -rf #{custom_key_directory}")
 
@@ -81,7 +81,7 @@
               'drop_privileges=false',
               "target='#{custom_key}'"]
       on(agent, puppet_resource('ssh_authorized_key', name.to_s, args), acceptable_exit_codes: [0, 1]) do |_res|
-        fail_test unless %r{the target path is not trusted}.match?(stderr)
+        fail_test unless stderr.include?('the target path is not trusted')
       end
     end
   end