diff --git a/lib/JSON/PP.pm b/lib/JSON/PP.pm
index 2a8b55a..81be0c7 100644
--- a/lib/JSON/PP.pm
+++ b/lib/JSON/PP.pm
@@ -904,7 +904,8 @@ BEGIN {
                             }
 
                             my $hex = hex( $u );
-                            if ( chr $u =~ /[[:^ascii:]]/ ) {
+
+                            if ($hex > 0x7f) {
                                 $is_utf8 = 1;
                                 $s .= JSON_PP_decode_unicode($u) || next;
                             }
diff --git a/t/014_latin1.t b/t/014_latin1.t
index cef9058..1f76b55 100644
--- a/t/014_latin1.t
+++ b/t/014_latin1.t
@@ -11,9 +11,9 @@ use JSON::PP;
 
 my $pp = JSON::PP->new->latin1->allow_nonref;
 
-ok ($pp->encode ("\x{12}\x{b6}       ") eq "\"\\u0012\x{b6}       \"");
-ok ($pp->encode ("\x{12}\x{b6}\x{abc}") eq "\"\\u0012\x{b6}\\u0abc\"");
+is($pp->encode ("\x{12}\x{b6}       "), "\"\\u0012\x{b6}       \"");
+is($pp->encode ("\x{12}\x{b6}\x{abc}"), "\"\\u0012\x{b6}\\u0abc\"");
 
-ok ($pp->decode ("\"\\u0012\x{b6}\""       ) eq "\x{12}\x{b6}");
-ok ($pp->decode ("\"\\u0012\x{b6}\\u0abc\"") eq "\x{12}\x{b6}\x{abc}");
+is($pp->decode ("\"\\u0012\x{b6}\""       ), "\x{12}\x{b6}");
+is($pp->decode ("\"\\u0012\x{b6}\\u0abc\""), "\x{12}\x{b6}\x{abc}");