diff --git a/lib/Data/MessagePack/PP.pm b/lib/Data/MessagePack/PP.pm
index 5d85c31..2d1f3ab 100644
--- a/lib/Data/MessagePack/PP.pm
+++ b/lib/Data/MessagePack/PP.pm
@@ -234,7 +234,7 @@ sub _pack {
     if ( $flags & B::SVp_POK ) { # raw / check needs before double
 
         if ( $self->{prefer_integer} ) {
-            if ( $value =~ /^-?[0-9]+$/ ) { # ok?
+            if ( $value =~ /^(0|-?[1-9][0-9]*)$/ ) { # ok?
                 # checks whether $value is in (u)int32
                 my $ivalue = 0 + $value;
                 if (!(
diff --git a/t/05_preferred_int.t b/t/05_preferred_int.t
index c1db9f3..4c68e8a 100644
--- a/t/05_preferred_int.t
+++ b/t/05_preferred_int.t
@@ -41,8 +41,10 @@ my @dat = (
     '',      'c4 00',
     '0',     '00',
     '1',     '01',
+    '01',    'c4 02 30 31',
     '10',    '0a',
     '-1',    'ff',
+    '-0',    'c4 02 2d 30',
     '-10',   'f6',
     '-',     'c4 01 2d',
     ''.0xEFFF => 'cd ef ff',
diff --git a/xs-src/pack.c b/xs-src/pack.c
index f09a747..15d9219 100644
--- a/xs-src/pack.c
+++ b/xs-src/pack.c
@@ -131,6 +131,8 @@ STATIC_INLINE int try_int(enc_t* enc, const char *p, size_t len) {
         if (len > 10) { return 0; }
     }
 
+    if (*p == '0' && len != 1) { return 0; }
+
 #if '9'=='8'+1 && '8'=='7'+1 && '7'=='6'+1 && '6'=='5'+1 && '5'=='4'+1 \
                && '4'=='3'+1 && '3'=='2'+1 && '2'=='1'+1 && '1'=='0'+1
     do {