--- Types-Serialiser/Serialiser.pm	2013/10/28 21:52:22	1.5
+++ Types-Serialiser/Serialiser.pm	2013/10/29 13:08:35	1.6
@@ -19,7 +19,7 @@
 
 use common::sense; # required to suppress annoying warnings
 
-our $VERSION = 0.02;
+our $VERSION = 0.03;
 
 =head1 SIMPLE SCALAR CONSTANTS
 
@@ -103,9 +103,24 @@
    # for historical reasons, and to avoid extra dependencies in JSON::PP,
    # we alias *Types::Serialiser::Boolean with JSON::PP::Boolean.
    package JSON::PP::Boolean;
+
    *Types::Serialiser::Boolean:: = *JSON::PP::Boolean::;
 }
 
+{
+   # this must done before blessing to work around bugs
+   # in perl < 5.18 (it seems to be fixed in 5.18).
+   package Types::Serialiser::BooleanBase;
+
+   use overload
+      "0+"     => sub { ${$_[0]} },
+      "++"     => sub { $_[0] = ${$_[0]} + 1 },
+      "--"     => sub { $_[0] = ${$_[0]} - 1 },
+      fallback => 1;
+
+   @Types::Serialiser::Boolean::ISA = Types::Serialiser::BooleanBase::;
+}
+
 our $true  = do { bless \(my $dummy = 1), Types::Serialiser::Boolean:: };
 our $false = do { bless \(my $dummy = 0), Types::Serialiser::Boolean:: };
 our $error = do { bless \(my $dummy    ), Types::Serialiser::Error::   };
@@ -119,16 +134,6 @@
 sub is_false ($) { !$_[0] && UNIVERSAL::isa $_[0], Types::Serialiser::Boolean:: }
 sub is_error ($) {           UNIVERSAL::isa $_[0], Types::Serialiser::Error::   }
 
-package Types::Serialiser::BooleanBase;
-
-use overload
-   "0+"     => sub { ${$_[0]} },
-   "++"     => sub { $_[0] = ${$_[0]} + 1 },
-   "--"     => sub { $_[0] = ${$_[0]} - 1 },
-   fallback => 1;
-
-@Types::Serialiser::Boolean::ISA = Types::Serialiser::BooleanBase::;
-
 package Types::Serialiser::Error;
 
 sub error {