diff --git a/lib/perlcritic/Perl/Critic/Policy/HashKeyQuotes.pm b/lib/perlcritic/Perl/Critic/Policy/HashKeyQuotes.pm
index 8290eab..1f27af4 100644
--- a/lib/perlcritic/Perl/Critic/Policy/HashKeyQuotes.pm
+++ b/lib/perlcritic/Perl/Critic/Policy/HashKeyQuotes.pm
@@ -23,7 +23,9 @@ sub violates ($self, $elem, $document) {
     # skip anything that's not a hash key
     return () unless is_hash_key($elem);
 
-    my $k = $elem->literal;
+    # only some PPI::Token::Quote::* classes implement literal
+    my $k = $elem->can('literal') ? $elem->literal : $elem->string;
+
     # skip anything that has a special symbol in the content
     return () unless $k =~ m/^\w+$/;
 
diff --git a/tools/perlcritic b/tools/perlcritic
index 80b85b4..07350a9 100755
--- a/tools/perlcritic
+++ b/tools/perlcritic
@@ -5,6 +5,7 @@
 # perlcritic with auto-injection of custom perlcritic rules.
 use strict;
 use warnings;
+use v5.10;
 use experimental 'signatures';
 use FindBin '$Bin';
 
@@ -16,5 +17,8 @@ sub extra_include_paths (@extra_paths) {
 }
 
 $ENV{PERL5LIB} = join(':', (extra_include_paths('lib/perlcritic'), $ENV{PERL5LIB} // ''));
-
+unless (@ARGV) {
+    say "Usage: $0 files-or-directories";
+    exit;
+}
 exec 'perlcritic', @ARGV;