diff --git a/perl/lib/Data/MessagePack/PP.pm b/perl/lib/Data/MessagePack/PP.pm
index 23942225..8234b493 100644
--- a/perl/lib/Data/MessagePack/PP.pm
+++ b/perl/lib/Data/MessagePack/PP.pm
@@ -103,8 +103,8 @@ BEGIN {
 
             *unpack_float  = sub { return unpack( 'f', substr( $_[0], $_[1], 4 ) ); };
             *unpack_double = sub { return unpack( 'd', substr( $_[0], $_[1], 8 ) ); };
-            *unpack_int64  = $unpack_int64_slow  || sub { pack 'q', substr( $_[0], $_[1], 8 ); };
-            *unpack_uint64 = $unpack_uint64_slow || sub { pack 'Q', substr( $_[0], $_[1], 8 ); };
+            *unpack_int64  = $unpack_int64_slow  || sub { unpack 'q', substr( $_[0], $_[1], 8 ); };
+            *unpack_uint64 = $unpack_uint64_slow || sub { unpack 'Q', substr( $_[0], $_[1], 8 ); };
         }
     }
     else {
@@ -419,7 +419,7 @@ sub execute {
 
     $p = 0;
 
-    LOOP: while ( length($self->{data}) > $p ) {
+    while ( length($self->{data}) > $p ) {
         _count( $self, $self->{data} ) or last;
 
         while ( @{ $self->{stack} } > 0 && --$self->{stack}->[-1] == 0) {
@@ -428,7 +428,7 @@ sub execute {
 
         if (@{$self->{stack}} == 0) {
             $self->{is_finished}++;
-            last LOOP;
+            last;
         }
     }
     $self->{pos} = $p;
@@ -455,7 +455,7 @@ sub _count {
             $num = $byte & ~0x90;
         }
 
-        if (defined($num) && $num > 0) {
+        if ( $num ) {
             push @{ $self->{stack} }, $num + 1;
         }
 
@@ -476,7 +476,7 @@ sub _count {
             $num = $byte & ~0x80;
         }
 
-        if ($num > 0) {
+        if ( $num ) {
             push @{ $self->{stack} }, $num * 2 + 1; # a pair
         }