diff --git a/perl/lib/Data/MessagePack/PP.pm b/perl/lib/Data/MessagePack/PP.pm
index bd37ad76..9e322991 100644
--- a/perl/lib/Data/MessagePack/PP.pm
+++ b/perl/lib/Data/MessagePack/PP.pm
@@ -25,19 +25,19 @@ BEGIN {
         # require $Config{byteorder}; my $bo_is_le = ( $Config{byteorder} =~ /^1234/ );
         # which better?
         my $bo_is_le = unpack ( 'd', "\x00\x00\x00\x00\x00\x00\xf0\x3f") == 1; # 1.0LE
-        # In really, since 5.9.2 '>' is introduced.
+        # In really, since 5.9.2 '>' is introduced. but 'n!' and 'N!'?
         *pack_uint64 = $bo_is_le ? sub {
             my @v = unpack( 'V2', pack( 'Q', $_[0] ) );
             return pack 'CN2', 0xcf, @v[1,0];
-        }  : sub { pack 'CQ', 0xcf, $_[0]; };
+        } : sub { pack 'CQ', 0xcf, $_[0]; };
         *pack_int64 = $bo_is_le ? sub {
             my @v = unpack( 'V2', pack( 'q', $_[0] ) );
             return pack 'CN2', 0xd3, @v[1,0];
-        }  : sub { pack 'Cq', 0xd3, $_[0]; };
+        } : sub { pack 'Cq', 0xd3, $_[0]; };
         *pack_double = $bo_is_le ? sub {
             my @v = unpack( 'V2', pack( 'd', $_[0] ) );
             return pack 'CN2', 0xcb, @v[1,0];
-        }  : sub { pack 'Cd', 0xcb, $_[0]; };
+        } : sub { pack 'Cd', 0xcb, $_[0]; };
         *unpack_float = $bo_is_le ? sub {
             my @v = unpack( 'v2', substr( $_[0], $_[1], 4 ) );
             return unpack( 'f', pack( 'n2', @v[1,0] ) );
@@ -55,14 +55,14 @@ BEGIN {
             my $v = unpack 'N', substr( $_[0], $_[1], 4 );
             return $v ? $v - 0x100000000 : 0;
         };
-        *unpack_int64 = sub {
+        *unpack_int64 = $bo_is_le ? sub {
             my @v = unpack( 'V*', substr( $_[0], $_[1], 8 ) );
             return unpack( 'q', pack( 'N2', @v[1,0] ) );
-        };
-        *unpack_uint64 = sub {
+        } : sub { pack 'q', substr( $_[0], $_[1], 8 ); };
+        *unpack_uint64 = $bo_is_le ? sub {
             my @v = unpack( 'V*', substr( $_[0], $_[1], 8 ) );
             return unpack( 'Q', pack( 'N2', @v[1,0] ) );
-        };
+        } : sub { pack 'Q', substr( $_[0], $_[1], 8 ); };
     }
     else {
         *pack_uint64   = sub { return pack 'CQ>', 0xcf, $_[0]; };