diff --git a/lib/puppet/ffi/windows/api_types.rb b/lib/puppet/ffi/windows/api_types.rb
index fc6485f89e..538d2dbedc 100644
--- a/lib/puppet/ffi/windows/api_types.rb
+++ b/lib/puppet/ffi/windows/api_types.rb
@@ -230,7 +230,7 @@ class GUID < FFI::Struct
                :Data4, [:byte, 8]
 
         def self.[](s)
-          raise _('Bad GUID format.') unless s =~ /^[0-9a-f]{8}-([0-9a-f]{4}-){3}[0-9a-f]{12}$/i
+          raise _('Bad GUID format.') unless s =~ /\A[0-9a-f]{8}-([0-9a-f]{4}-){3}[0-9a-f]{12}\z/i
 
           new.tap do |guid|
             guid[:Data1] = s[0, 8].to_i(16)
diff --git a/lib/puppet/interface/action.rb b/lib/puppet/interface/action.rb
index e330ed6e0b..3ee494eab5 100644
--- a/lib/puppet/interface/action.rb
+++ b/lib/puppet/interface/action.rb
@@ -14,7 +14,7 @@ class Puppet::Interface::Action
 
   # @api private
   def initialize(face, name)
-    raise "#{name.inspect} is an invalid action name" unless name.to_s =~ /^[a-z]\w*$/
+    raise "#{name.inspect} is an invalid action name" unless name.to_s =~ /\A[a-z]\w*\z/
 
     @face    = face
     @name    = name.to_sym