diff --git a/src/CXX/Python3/Objects.hxx b/src/CXX/Python3/Objects.hxx
index e5b341a012..eb7afc885b 100644
--- a/src/CXX/Python3/Objects.hxx
+++ b/src/CXX/Python3/Objects.hxx
@@ -54,7 +54,7 @@
 
 namespace Py
 {
-    typedef size_t sequence_index_type;    // type of an index into a sequence
+    typedef Py_ssize_t sequence_index_type;    // type of an index into a sequence
 
     // Forward declarations
     class Object;
@@ -1095,7 +1095,7 @@ namespace Py
     {
     protected:
         SeqBase<T> &s; // the sequence
-        size_t offset; // item number
+        sequence_index_type offset; // item number
         T the_item; // lvalue
 
     public:
@@ -1289,7 +1289,7 @@ namespace Py
     {
     public:
         // STL definitions
-        typedef size_t size_type;
+        typedef Py_ssize_t size_type;
         typedef seqref<T> reference;
         typedef T const_reference;
         typedef seqref<T> *pointer;
@@ -1298,7 +1298,8 @@ namespace Py
 
         virtual size_type max_size() const
         {
-            return std::string::npos; // ?
+            //return std::string::npos; // ?
+            return std::numeric_limits<size_type>::max();
         }
 
         virtual size_type capacity() const
@@ -1822,7 +1823,7 @@ namespace Py
         // Assignment from C string
         Byte &operator=( const std::string &v )
         {
-            set( PyBytes_FromStringAndSize( const_cast<char*>( v.c_str() ),1 ), true );
+            set( PyBytes_FromStringAndSize( const_cast<char*>( v.c_str() ), 1 ), true );
             return *this;
         }
 
@@ -1869,13 +1870,13 @@ namespace Py
         }
 
         Bytes( const std::string &v )
-        : SeqBase<Byte>( PyBytes_FromStringAndSize( const_cast<char*>( v.data() ), static_cast<int>( v.length() ) ), true )
+        : SeqBase<Byte>( PyBytes_FromStringAndSize( const_cast<char*>( v.data() ), v.length() ), true )
         {
             validate();
         }
 
         Bytes( const std::string &v, Py_ssize_t vsize )
-        : SeqBase<Byte>( PyBytes_FromStringAndSize( const_cast<char*>( v.data() ), static_cast<int>( vsize ) ), true )
+        : SeqBase<Byte>( PyBytes_FromStringAndSize( const_cast<char*>( v.data() ), vsize ), true )
         {
             validate();
         }
@@ -1908,7 +1909,7 @@ namespace Py
         // Assignment from C string
         Bytes &operator=( const std::string &v )
         {
-            set( PyBytes_FromStringAndSize( const_cast<char*>( v.data() ), static_cast<int>( v.length() ) ), true );
+            set( PyBytes_FromStringAndSize( const_cast<char*>( v.data() ), v.length() ), true );
             return *this;
         }
 
@@ -1917,7 +1918,7 @@ namespace Py
         // Queries
         virtual size_type size() const
         {
-            return static_cast<size_type>( PyBytes_Size( ptr() ) );
+            return PyBytes_Size( ptr() );
         }
 
         operator std::string() const
@@ -1927,7 +1928,7 @@ namespace Py
 
         std::string as_std_string() const
         {
-            return std::string( PyBytes_AsString( ptr() ), static_cast<size_type>( PyBytes_Size( ptr() ) ) );
+            return std::string( PyBytes_AsString( ptr() ), static_cast<size_t>( PyBytes_Size( ptr() ) ) );
         }
     };
 
@@ -2112,7 +2113,7 @@ namespace Py
 
         String &operator=( const unicodestring &v )
         {
-            set( PyUnicode_FromUnicode( const_cast<Py_UNICODE *>( v.data() ), static_cast<int>( v.length() ) ), true );
+            set( PyUnicode_FromUnicode( const_cast<Py_UNICODE *>( v.data() ), v.length() ), true );
             return *this;
         }
 
@@ -2125,12 +2126,12 @@ namespace Py
         // Queries
         virtual size_type size() const
         {
-            return static_cast<size_type>( PyUnicode_GET_SIZE( ptr() ) );
+            return PyUnicode_GET_SIZE( ptr() );
         }
 
         unicodestring as_unicodestring() const
         {
-            return unicodestring( PyUnicode_AS_UNICODE( ptr() ), static_cast<size_type>( PyUnicode_GET_SIZE( ptr() ) ) );
+            return unicodestring( PyUnicode_AS_UNICODE( ptr() ), PyUnicode_GET_SIZE( ptr() ) );
         }
 
         operator std::string() const
@@ -2179,7 +2180,7 @@ namespace Py
         }
 
         // New tuple of a given size
-        explicit Tuple( sequence_index_type size = 0 )
+        explicit Tuple( size_type size=0 )
         {
             set( PyTuple_New( size ), true );
             validate();
@@ -2198,7 +2199,7 @@ namespace Py
 
             set( PyTuple_New( limit ), true );
             validate();
-            
+
             for( sequence_index_type i=0; i < limit; i++ )
             {
                 if( PyTuple_SetItem( ptr(), i, new_reference_to( s[i] ) ) == -1 )
@@ -2237,7 +2238,7 @@ namespace Py
     {
     public:
         TupleN()
-        : Tuple( (sequence_index_type)0 )
+        : Tuple( (size_type)0 )
         {
         }
 
@@ -2362,7 +2363,7 @@ namespace Py
             validate();
         }
         // Creation at a fixed size
-        List( sequence_index_type size = 0 )
+        List( size_type size = 0 )
         {
             set( PyList_New( size ), true );
             validate();
@@ -2379,7 +2380,7 @@ namespace Py
         List( const Sequence &s )
         : Sequence()
         {
-            sequence_index_type n =( int )s.length();
+            size_type n = s.length();
             set( PyList_New( n ), true );
             validate();
             for( sequence_index_type i=0; i < n; i++ )
@@ -2659,7 +2660,7 @@ namespace Py
         // If you assume that Python mapping is a hash_map...
         // hash_map::value_type is not assignable, but
         //( *it ).second = data must be a valid expression
-        typedef size_t size_type;
+        typedef Py_ssize_t size_type;
         typedef Object key_type;
         typedef mapref<T> data_type;
         typedef std::pair< const T, T > value_type;