diff --git a/bind/gencpy.go b/bind/gencpy.go
index ce49438..f06bf6a 100644
--- a/bind/gencpy.go
+++ b/bind/gencpy.go
@@ -53,19 +53,43 @@ typedef struct _gopy_object gopy_object;
 
 // --- gopy object model ---
 
+typedef GoUint8 *cgo_type_bool;
+typedef GoUint8 *cgo_type_byte;
+
+typedef GoInt   *cgo_type_int;
+typedef GoInt8  *cgo_type_int8;
+typedef GoInt16 *cgo_type_int16;
+typedef GoInt32 *cgo_type_int32;
+typedef GoInt64 *cgo_type_int64;
+
+typedef GoUint   *cgo_type_uint;
+typedef GoUint8  *cgo_type_uint8;
+typedef GoUint16 *cgo_type_uint16;
+typedef GoUint32 *cgo_type_uint32;
+typedef GoUint64 *cgo_type_uint64;
+
+typedef GoFloat32    *cgo_type_float32;
+typedef GoFloat64    *cgo_type_float64;
+typedef GoComplex64  *cgo_type_complex64;
+typedef GoComplex128 *cgo_type_complex128;
+
+typedef GoString *cgo_type_string;
+typedef void     *cgo_type_rune; /* FIXME */
+
+typedef GoInterface *cgo_type_interface;
 
 // helpers for cgopy
 
 #define def_cnv(name, c2py, py2c, gotype) \
 	static int \
-	cgopy_cnv_py2c_ ## name(PyObject *o, gotype *addr) { \
-		*addr = py2c(o); \
+	cgopy_cnv_py2c_ ## name(PyObject *o, cgo_type_ ## name *addr) { \
+		**((gotype**)addr) = py2c(o); \
 		return 1;	\
 	} \
 	\
 	static PyObject* \
-	cgopy_cnv_c2py_ ## name(gotype *addr) { \
-		return c2py(*addr); \
+	cgopy_cnv_c2py_ ## name(cgo_type_ ## name *addr) { \
+		return c2py(**((gotype**)addr)); \
 	} 
 
 #if (GOINTBITS == 4)
@@ -76,11 +100,12 @@ typedef struct _gopy_object gopy_object;
 	def_cnv(uint,  PyInt_FromLong, PyInt_AsLong, GoUint)
 #endif
 
-def_cnv(  int8, PyInt_FromLong, PyInt_AsLong, GoInt8)
-def_cnv( int16, PyInt_FromLong, PyInt_AsLong, GoInt16)
-def_cnv( int32, PyInt_FromLong, PyInt_AsLong, GoInt32)
+def_cnv(  int8,  PyInt_FromLong,  PyInt_AsLong,  GoInt8)
+def_cnv( int16,  PyInt_FromLong,  PyInt_AsLong, GoInt16)
+def_cnv( int32,  PyInt_FromLong,  PyInt_AsLong, GoInt32)
 def_cnv( int64, PyLong_FromLong, PyLong_AsLong, GoInt64)
-def_cnv(uint8,  PyInt_FromLong, PyInt_AsLong, GoUint8)
+
+def_cnv( uint8, PyInt_FromLong, PyInt_AsLong,  GoUint8)
 def_cnv(uint16, PyInt_FromLong, PyInt_AsLong, GoUint16)
 def_cnv(uint32, PyInt_FromLong, PyInt_AsLong, GoUint32)
 def_cnv(uint64, PyLong_FromUnsignedLong, PyLong_AsUnsignedLong, GoUint64)
@@ -90,70 +115,72 @@ def_cnv(float64, PyFloat_FromDouble, PyFloat_AsDouble, GoFloat64)
 #undef def_cnv
 
 static int
-cgopy_cnv_py2c_bool(PyObject *o, GoUint8 *addr) {
-	*addr = (o == Py_True) ? 1 : 0;
+cgopy_cnv_py2c_bool(PyObject *o, cgo_type_bool *addr) {
+	**(GoUint8**)addr = (o == Py_True) ? 1 : 0;
 	return 1;
 }
 
 static PyObject*
-cgopy_cnv_c2py_bool(GoUint8 *addr) {
-	long v = *addr;
+cgopy_cnv_c2py_bool(cgo_type_bool *addr) {
+	long v = **(GoUint8**)addr;
 	return PyBool_FromLong(v);
 }
 
 static int
-cgopy_cnv_py2c_string(PyObject *o, GoString *addr) {
+cgopy_cnv_py2c_string(PyObject *o, cgo_type_string *addr) {
 	const char *str = PyString_AsString(o);
 	if (str == NULL) {
 		return 0;
 	}
-	*addr = _cgopy_GoString((char*)str);
+	**((GoString**)addr) = _cgopy_GoString((char*)str);
 	return 1;
 }
 
 static PyObject*
-cgopy_cnv_c2py_string(GoString *addr) {
-	const char *str = _cgopy_CString(*addr);
+cgopy_cnv_c2py_string(cgo_type_string *addr) {
+	const char *str = _cgopy_CString(**(GoString**)addr);
 	PyObject *pystr = PyString_FromString(str);
 	free((void*)str);
 	return pystr;
 }
 
 static int
-cgopy_cnv_py2c_float32(PyObject *o, GoFloat32 *addr) {
-	GoFloat32 v = PyFloat_AsDouble(o);
-	*addr = v;
+cgopy_cnv_py2c_float32(PyObject *o, cgo_type_float32 *addr) {
+	GoFloat64 v = PyFloat_AsDouble(o);
+	**(GoFloat32**)addr = v;
 	return 1;
 }
 
 static PyObject*
-cgopy_cnv_c2py_float32(GoFloat32 *addr) {
-	GoFloat64 v = *addr;
+cgopy_cnv_c2py_float32(cgo_type_float32 *addr) {
+	GoFloat64 v = **(GoFloat32**)addr;
 	return PyFloat_FromDouble(v);
 }
 
 static int
-cgopy_cnv_py2c_complex64(PyObject *o, GoComplex64 *addr) {
+cgopy_cnv_py2c_complex64(PyObject *o, cgo_type_complex64 *addr) {
 	Py_complex v = PyComplex_AsCComplex(o);
-	*addr = v.real + v.imag * _Complex_I;
+	**(GoComplex64**)addr = v.real + v.imag * _Complex_I;
 	return 1;
 }
 
 static PyObject*
-cgopy_cnv_c2py_complex64(GoComplex64 *addr) {
-	return PyComplex_FromDoubles(creal(*addr), cimag(*addr));
+cgopy_cnv_c2py_complex64(cgo_type_complex64 *addr) {
+	GoComplex64 v = **(GoComplex64**)addr;
+	return PyComplex_FromDoubles(creal(v), cimag(v));
 }
 
 static int
-cgopy_cnv_py2c_complex128(PyObject *o, GoComplex128 *addr) {
+cgopy_cnv_py2c_complex128(PyObject *o, cgo_type_complex128 *addr) {
 	Py_complex v = PyComplex_AsCComplex(o);
-	*addr = v.real + v.imag * _Complex_I;
+	**(GoComplex128**)addr = v.real + v.imag * _Complex_I;
 	return 1;
 }
 
 static PyObject*
-cgopy_cnv_c2py_complex128(GoComplex128 *addr) {
-	return PyComplex_FromDoubles(creal(*addr), cimag(*addr));
+cgopy_cnv_c2py_complex128(cgo_type_complex128 *addr) {
+	GoComplex128 v = **(GoComplex128**)addr;
+	return PyComplex_FromDoubles(creal(v), cimag(v));
 }
 `
 )
diff --git a/bind/gencpy_func.go b/bind/gencpy_func.go
index 9977a3c..e0e2600 100644
--- a/bind/gencpy_func.go
+++ b/bind/gencpy_func.go
@@ -150,9 +150,9 @@ func (g *cpyGen) _genFunc(sym *symbol, fsym *symbol) {
 	if hasError(sig) {
 		switch nres {
 		case 1:
-			g.impl.Printf("if (!_cgopy_ErrorIsNil(ret)) {\n")
+			g.impl.Printf("if (!_cgopy_ErrorIsNil(*(GoInterface*)(ret))) {\n")
 			g.impl.Indent()
-			g.impl.Printf("const char* c_err_str = _cgopy_ErrorString(ret);\n")
+			g.impl.Printf("const char* c_err_str = _cgopy_ErrorString(*(GoInterface*)(ret));\n")
 			g.impl.Printf("PyErr_SetString(PyExc_RuntimeError, c_err_str);\n")
 			g.impl.Printf("free((void*)c_err_str);\n")
 			g.impl.Printf("return NULL;\n")
@@ -164,9 +164,9 @@ func (g *cpyGen) _genFunc(sym *symbol, fsym *symbol) {
 			return
 
 		case 2:
-			g.impl.Printf("if (!_cgopy_ErrorIsNil(ret.r1)) {\n")
+			g.impl.Printf("if (!_cgopy_ErrorIsNil(*(GoInterface*)(ret.r1))) {\n")
 			g.impl.Indent()
-			g.impl.Printf("const char* c_err_str = _cgopy_ErrorString(ret.r1);\n")
+			g.impl.Printf("const char* c_err_str = _cgopy_ErrorString(*(GoInterface*)(ret.r1));\n")
 			g.impl.Printf("PyErr_SetString(PyExc_RuntimeError, c_err_str);\n")
 			g.impl.Printf("free((void*)c_err_str);\n")
 			g.impl.Printf("return NULL;\n")
@@ -286,9 +286,9 @@ func (g *cpyGen) genFuncBody(f Func) {
 	if f.err {
 		switch len(res) {
 		case 1:
-			g.impl.Printf("if (!_cgopy_ErrorIsNil(c_gopy_ret)) {\n")
+			g.impl.Printf("if (!_cgopy_ErrorIsNil(*(GoInterface*)(c_gopy_ret))) {\n")
 			g.impl.Indent()
-			g.impl.Printf("const char* c_err_str = _cgopy_ErrorString(c_gopy_ret);\n")
+			g.impl.Printf("const char* c_err_str = _cgopy_ErrorString(*(GoInterface*)(c_gopy_ret));\n")
 			g.impl.Printf("PyErr_SetString(PyExc_RuntimeError, c_err_str);\n")
 			g.impl.Printf("free((void*)c_err_str);\n")
 			g.impl.Printf("return NULL;\n")
@@ -298,9 +298,9 @@ func (g *cpyGen) genFuncBody(f Func) {
 			return
 
 		case 2:
-			g.impl.Printf("if (!_cgopy_ErrorIsNil(c_gopy_ret.r1)) {\n")
+			g.impl.Printf("if (!_cgopy_ErrorIsNil(*(GoInterface*)(c_gopy_ret.r1))) {\n")
 			g.impl.Indent()
-			g.impl.Printf("const char* c_err_str = _cgopy_ErrorString(c_gopy_ret.r1);\n")
+			g.impl.Printf("const char* c_err_str = _cgopy_ErrorString(*(GoInterface*)(c_gopy_ret.r1));\n")
 			g.impl.Printf("PyErr_SetString(PyExc_RuntimeError, c_err_str);\n")
 			g.impl.Printf("free((void*)c_err_str);\n")
 			g.impl.Printf("return NULL;\n")
diff --git a/bind/gencpy_struct.go b/bind/gencpy_struct.go
index 7f591d9..8abcddf 100644
--- a/bind/gencpy_struct.go
+++ b/bind/gencpy_struct.go
@@ -263,14 +263,12 @@ func (g *cpyGen) genStructMemberGetter(cpy Struct, i int, f types.Object) {
 		results      = []*Var{ifield}
 	)
 
-	if needWrapType(ft) {
-		g.decl.Printf("\n/* wrapper for field %s.%s.%s */\n",
-			pkg.Name(),
-			cpy.GoName(),
-			f.Name(),
-		)
-		g.decl.Printf("typedef void* %[1]s_field_%d;\n", cpy.sym.cgoname, i+1)
-	}
+	g.decl.Printf("\n/* wrapper for field %s.%s.%s */\n",
+		pkg.Name(),
+		cpy.GoName(),
+		f.Name(),
+	)
+	g.decl.Printf("typedef void* %[1]s_field_%d;\n", cpy.sym.cgoname, i+1)
 
 	g.decl.Printf("\n/* getter for %[1]s.%[2]s.%[3]s */\n",
 		pkg.Name(), cpy.sym.goname, f.Name(),
@@ -297,9 +295,7 @@ func (g *cpyGen) genStructMemberGetter(cpy Struct, i int, f types.Object) {
 
 	g.impl.Printf("PyObject *o = NULL;\n")
 	ftname := g.pkg.syms.symtype(ft).cgoname
-	if needWrapType(ft) {
-		ftname = fmt.Sprintf("%[1]s_field_%d", cpy.sym.cgoname, i+1)
-	}
+	ftname = fmt.Sprintf("%[1]s_field_%d", cpy.sym.cgoname, i+1)
 	g.impl.Printf(
 		"%[1]s c_ret = %[2]s(self->cgopy); /*wrap*/\n",
 		ftname,
diff --git a/bind/gencpy_type.go b/bind/gencpy_type.go
index 83a45f2..7e088ee 100644
--- a/bind/gencpy_type.go
+++ b/bind/gencpy_type.go
@@ -324,7 +324,6 @@ func (g *cpyGen) genTypeInit(sym *symbol) {
 		g.impl.Outdent()
 		g.impl.Printf("}\n\n") // if-arg
 
-
 	case sym.isMap():
 		g.impl.Printf("if (arg != NULL) {\n")
 		g.impl.Indent()
@@ -449,7 +448,7 @@ func (g *cpyGen) genTypeTPStr(sym *symbol) {
 		sym.cgoname,
 		sym.cpyname,
 	)
-	g.impl.Printf("GoString str = cgo_func_%[1]s_str(c_self);\n",
+	g.impl.Printf("cgo_type_string str = cgo_func_%[1]s_str(c_self);\n",
 		sym.id,
 	)
 	g.impl.Printf("return cgopy_cnv_c2py_string(&str);\n")
@@ -992,9 +991,9 @@ func (g *cpyGen) genTypeTPCall(sym *symbol) {
 	if hasError(sig) {
 		switch len(res) {
 		case 1:
-			g.impl.Printf("if (!_cgopy_ErrorIsNil(c_gopy_ret)) {\n")
+			g.impl.Printf("if (!_cgopy_ErrorIsNil(*(GoInterface*)(c_gopy_ret))) {\n")
 			g.impl.Indent()
-			g.impl.Printf("const char* c_err_str = _cgopy_ErrorString(c_gopy_ret);\n")
+			g.impl.Printf("const char* c_err_str = _cgopy_ErrorString(*(GoInterface*)(c_gopy_ret));\n")
 			g.impl.Printf("PyErr_SetString(PyExc_RuntimeError, c_err_str);\n")
 			g.impl.Printf("free((void*)c_err_str);\n")
 			g.impl.Printf("return NULL;\n")
@@ -1006,9 +1005,9 @@ func (g *cpyGen) genTypeTPCall(sym *symbol) {
 			return
 
 		case 2:
-			g.impl.Printf("if (!_cgopy_ErrorIsNil(c_gopy_ret.r1)) {\n")
+			g.impl.Printf("if (!_cgopy_ErrorIsNil(*(GoInterface*)(c_gopy_ret.r1))) {\n")
 			g.impl.Indent()
-			g.impl.Printf("const char* c_err_str = _cgopy_ErrorString(c_gopy_ret.r1);\n")
+			g.impl.Printf("const char* c_err_str = _cgopy_ErrorString(*(GoInterface*)(c_gopy_ret.r1));\n")
 			g.impl.Printf("PyErr_SetString(PyExc_RuntimeError, c_err_str);\n")
 			g.impl.Printf("free((void*)c_err_str);\n")
 			g.impl.Printf("return NULL;\n")
diff --git a/bind/gengo.go b/bind/gengo.go
index 29a4814..fc709d4 100644
--- a/bind/gengo.go
+++ b/bind/gengo.go
@@ -36,6 +36,12 @@ import (
 var _ = unsafe.Pointer(nil)
 var _ = fmt.Sprintf
 
+// --- begin cgo builtin types ---
+
+%[4]s
+
+// --- end cgo builtin types ---
+
 // --- begin cgo helpers ---
 
 //export _cgopy_GoString
@@ -235,17 +241,14 @@ func (g *goGen) genFuncBody(f Func) {
 		if i+1 < len(args) {
 			tail = ", "
 		}
-		head := arg.Name()
-		if arg.needWrap() {
-			head = fmt.Sprintf(
-				"*(*%s)(unsafe.Pointer(%s))",
-				types.TypeString(
-					arg.GoType(),
-					func(*types.Package) string { return g.pkg.Name() },
-				),
-				arg.Name(),
-			)
-		}
+		head := fmt.Sprintf(
+			"*(*%s)(unsafe.Pointer(%s))",
+			types.TypeString(
+				arg.GoType(),
+				func(*types.Package) string { return g.pkg.Name() },
+			),
+			arg.Name(),
+		)
 		g.Printf("%s%s", head, tail)
 	}
 	g.Printf(")\n")
@@ -254,10 +257,7 @@ func (g *goGen) genFuncBody(f Func) {
 		return
 	}
 
-	for i, res := range results {
-		if !res.needWrap() {
-			continue
-		}
+	for i := range results {
 		g.Printf("cgopy_incref(unsafe.Pointer(&_gopy_%03d))\n", i)
 	}
 
@@ -266,16 +266,7 @@ func (g *goGen) genFuncBody(f Func) {
 		if i > 0 {
 			g.Printf(", ")
 		}
-		// if needWrap(res.GoType()) {
-		// 	g.Printf("")
-		// }
-		if res.needWrap() {
-			g.Printf("%s(unsafe.Pointer(&", res.sym.cgoname)
-		}
-		g.Printf("_gopy_%03d", i)
-		if res.needWrap() {
-			g.Printf("))")
-		}
+		g.Printf("%s(unsafe.Pointer(&_gopy_%03d))", res.sym.cgoname, i)
 	}
 	g.Printf("\n")
 }
@@ -296,12 +287,9 @@ func (g *goGen) genStruct(s Struct) {
 
 		ft := f.Type()
 		fsym := g.pkg.syms.symtype(ft)
-		ftname := fsym.cgotypename()
-		if needWrapType(ft) {
-			ftname = fmt.Sprintf("cgo_type_%[1]s_field_%d", s.ID(), i+1)
-			g.Printf("//export %s\n", ftname)
-			g.Printf("type %s unsafe.Pointer\n\n", ftname)
-		}
+		ftname := fmt.Sprintf("cgo_type_%[1]s_field_%d", s.ID(), i+1)
+		g.Printf("//export %s\n", ftname)
+		g.Printf("type %s unsafe.Pointer\n\n", ftname)
 
 		// -- getter --
 
@@ -316,12 +304,8 @@ func (g *goGen) genStruct(s Struct) {
 			s.sym.gofmt(),
 		)
 
-		if !fsym.isBasic() {
-			g.Printf("cgopy_incref(unsafe.Pointer(&ret.%s))\n", f.Name())
-			g.Printf("return %s(unsafe.Pointer(&ret.%s))\n", ftname, f.Name())
-		} else {
-			g.Printf("return ret.%s\n", f.Name())
-		}
+		g.Printf("cgopy_incref(unsafe.Pointer(&ret.%s))\n", f.Name())
+		g.Printf("return %s(unsafe.Pointer(&ret.%s))\n", ftname, f.Name())
 		g.Outdent()
 		g.Printf("}\n\n")
 
@@ -332,9 +316,7 @@ func (g *goGen) genStruct(s Struct) {
 		)
 		g.Indent()
 		fset := "v"
-		if !fsym.isBasic() {
-			fset = fmt.Sprintf("*(*%s)(unsafe.Pointer(v))", fsym.gofmt())
-		}
+		fset = fmt.Sprintf("*(*%s)(unsafe.Pointer(v))", fsym.gofmt())
 		g.Printf(
 			"(*%[1]s)(unsafe.Pointer(self)).%[2]s = %[3]s\n",
 			s.sym.gofmt(),
@@ -366,11 +348,7 @@ func (g *goGen) genStruct(s Struct) {
 	)
 	g.Indent()
 	g.Printf("var v interface{} = ")
-	if s.sym.isBasic() {
-		g.Printf("%[1]s(self)\n", s.sym.gofmt())
-	} else {
-		g.Printf("*(*%[1]s)(unsafe.Pointer(self))\n", s.sym.gofmt())
-	}
+	g.Printf("*(*%[1]s)(unsafe.Pointer(self))\n", s.sym.gofmt())
 	g.Printf("return v\n")
 	g.Outdent()
 	g.Printf("}\n\n")
@@ -378,19 +356,22 @@ func (g *goGen) genStruct(s Struct) {
 	// support for __str__
 	g.Printf("//export cgo_func_%[1]s_str\n", s.ID())
 	g.Printf(
-		"func cgo_func_%[1]s_str(self %[2]s) string {\n",
+		"func cgo_func_%[1]s_str(self %[2]s) cgo_type_string {\n",
 		s.ID(),
 		s.sym.cgoname,
 	)
 	g.Indent()
+	g.Printf("o := ")
 	if (s.prots & ProtoStringer) == 0 {
-		g.Printf("return fmt.Sprintf(\"%%#v\", ")
+		g.Printf("fmt.Sprintf(\"%%#v\", ")
 		g.Printf("*(*%[1]s)(unsafe.Pointer(self)))\n", s.sym.gofmt())
 	} else {
-		g.Printf("return (*%[1]s)(unsafe.Pointer(self)).String()\n",
+		g.Printf("(*%[1]s)(unsafe.Pointer(self)).String()\n",
 			s.sym.gofmt(),
 		)
 	}
+	g.Printf("cgopy_incref(unsafe.Pointer(&o))\n")
+	g.Printf("return (cgo_type_string)(unsafe.Pointer(&o))\n")
 	g.Outdent()
 	g.Printf("}\n\n")
 }
@@ -440,7 +421,15 @@ func (g *goGen) genMethodBody(s Struct, m Func) {
 		if i+1 < len(args) {
 			tail = ", "
 		}
-		g.Printf("%s%s", arg.Name(), tail)
+		head := fmt.Sprintf(
+			"*(*%s)(unsafe.Pointer(%s))",
+			types.TypeString(
+				arg.GoType(),
+				func(*types.Package) string { return g.pkg.Name() },
+			),
+			arg.Name(),
+		)
+		g.Printf("%s%s", head, tail)
 	}
 	g.Printf(")\n")
 
@@ -448,21 +437,16 @@ func (g *goGen) genMethodBody(s Struct, m Func) {
 		return
 	}
 
+	for i := range results {
+		g.Printf("cgopy_incref(unsafe.Pointer(&_gopy_%03d))\n", i)
+	}
+
 	g.Printf("return ")
 	for i, res := range results {
 		if i > 0 {
 			g.Printf(", ")
 		}
-		// if needWrap(res.GoType()) {
-		// 	g.Printf("")
-		// }
-		if res.needWrap() {
-			g.Printf("%s(unsafe.Pointer(&", res.sym.cgoname)
-		}
-		g.Printf("_gopy_%03d", i)
-		if res.needWrap() {
-			g.Printf("))")
-		}
+		g.Printf("%s(unsafe.Pointer(&_gopy_%03d))", res.sym.cgoname, i)
 	}
 	g.Printf("\n")
 
@@ -471,32 +455,27 @@ func (g *goGen) genMethodBody(s Struct, m Func) {
 func (g *goGen) genConst(o Const) {
 	sym := o.sym
 	g.Printf("//export cgo_func_%s_get\n", o.id)
-	g.Printf("func cgo_func_%[1]s_get() %[2]s {\n", o.id, sym.cgotypename())
+	g.Printf("func cgo_func_%[1]s_get() %[2]s {\n", o.id, sym.cgoname)
 	g.Indent()
-	g.Printf("return %s(%s.%s)\n", sym.cgotypename(), o.pkg.Name(), o.obj.Name())
+	g.Printf("v := %s.%s\n", o.pkg.Name(), o.obj.Name())
+	g.Printf("cgopy_incref(unsafe.Pointer(&v))\n")
+	g.Printf("return (%s)(unsafe.Pointer(&v))\n", sym.cgoname)
 	g.Outdent()
 	g.Printf("}\n\n")
 }
 
 func (g *goGen) genVar(o Var) {
 	pkgname := o.pkg.Name()
-	typ := o.GoType()
-	ret := o.sym.cgotypename()
+	ret := o.sym.cgoname
 
 	g.Printf("//export cgo_func_%s_get\n", o.id)
 	g.Printf("func cgo_func_%[1]s_get() %[2]s {\n", o.id, ret)
 	g.Indent()
-	if o.needWrap() {
-		g.Printf("cgopy_incref(unsafe.Pointer(&%s.%s))\n", pkgname, o.Name())
-	}
+	g.Printf("cgopy_incref(unsafe.Pointer(&%s.%s))\n", pkgname, o.Name())
 	g.Printf("return ")
-	if o.needWrap() {
-		g.Printf("%s(unsafe.Pointer(&%s.%s))",
-			ret, pkgname, o.Name(),
-		)
-	} else {
-		g.Printf("%s(%s.%s)", ret, pkgname, o.Name())
-	}
+	g.Printf("%s(unsafe.Pointer(&%s.%s))",
+		ret, pkgname, o.Name(),
+	)
 	g.Printf("\n")
 	g.Outdent()
 	g.Printf("}\n\n")
@@ -504,12 +483,7 @@ func (g *goGen) genVar(o Var) {
 	g.Printf("//export cgo_func_%s_set\n", o.id)
 	g.Printf("func cgo_func_%[1]s_set(v %[2]s) {\n", o.id, ret)
 	g.Indent()
-	vset := "v"
-	if needWrapType(typ) {
-		vset = fmt.Sprintf("*(*%s)(unsafe.Pointer(v))", o.sym.gofmt())
-	} else {
-		vset = fmt.Sprintf("%s(v)", o.sym.gofmt())
-	}
+	vset := fmt.Sprintf("*(*%s)(unsafe.Pointer(v))", o.sym.gofmt())
 	g.Printf(
 		"%[1]s.%[2]s = %[3]s\n",
 		pkgname, o.Name(), vset,
@@ -532,23 +506,13 @@ func (g *goGen) genType(sym *symbol) {
 	g.Printf("\n// --- wrapping %s ---\n\n", sym.gofmt())
 	g.Printf("//export %[1]s\n", sym.cgoname)
 	g.Printf("// %[1]s wraps %[2]s\n", sym.cgoname, sym.gofmt())
-	if sym.isBasic() {
-		// we need to reach at the underlying type
-		btyp := sym.GoType().Underlying().String()
-		g.Printf("type %[1]s %[2]s\n\n", sym.cgoname, btyp)
-	} else {
-		g.Printf("type %[1]s unsafe.Pointer\n\n", sym.cgoname)
-	}
+	g.Printf("type %[1]s unsafe.Pointer\n\n", sym.cgoname)
 	g.Printf("//export cgo_func_%[1]s_new\n", sym.id)
 	g.Printf("func cgo_func_%[1]s_new() %[2]s {\n", sym.id, sym.cgoname)
 	g.Indent()
 	g.Printf("var o %[1]s\n", sym.gofmt())
-	if sym.isBasic() {
-		g.Printf("return %[1]s(o)\n", sym.cgoname)
-	} else {
-		g.Printf("cgopy_incref(unsafe.Pointer(&o))\n")
-		g.Printf("return (%[1]s)(unsafe.Pointer(&o))\n", sym.cgoname)
-	}
+	g.Printf("cgopy_incref(unsafe.Pointer(&o))\n")
+	g.Printf("return (%[1]s)(unsafe.Pointer(&o))\n", sym.cgoname)
 	g.Outdent()
 	g.Printf("}\n\n")
 
@@ -560,11 +524,7 @@ func (g *goGen) genType(sym *symbol) {
 	)
 	g.Indent()
 	g.Printf("var v interface{} = ")
-	if sym.isBasic() {
-		g.Printf("%[1]s(self)\n", sym.gofmt())
-	} else {
-		g.Printf("*(*%[1]s)(unsafe.Pointer(self))\n", sym.gofmt())
-	}
+	g.Printf("*(*%[1]s)(unsafe.Pointer(self))\n", sym.gofmt())
 	g.Printf("return v\n")
 	g.Outdent()
 	g.Printf("}\n\n")
@@ -572,17 +532,16 @@ func (g *goGen) genType(sym *symbol) {
 	// support for __str__
 	g.Printf("//export cgo_func_%[1]s_str\n", sym.id)
 	g.Printf(
-		"func cgo_func_%[1]s_str(self %[2]s) string {\n",
+		"func cgo_func_%[1]s_str(self %[2]s) cgo_type_string {\n",
 		sym.id,
 		sym.cgoname,
 	)
 	g.Indent()
-	g.Printf("return fmt.Sprintf(\"%%#v\", ")
-	if sym.isBasic() {
-		g.Printf("%[1]s(self))\n", sym.gofmt())
-	} else {
-		g.Printf("*(*%[1]s)(unsafe.Pointer(self)))\n", sym.gofmt())
-	}
+	g.Printf("o := ")
+	g.Printf("fmt.Sprintf(\"%%#v\", ")
+	g.Printf("*(*%[1]s)(unsafe.Pointer(self)))\n", sym.gofmt())
+	g.Printf("cgopy_incref(unsafe.Pointer(&o))\n")
+	g.Printf("return (cgo_type_string)(unsafe.Pointer(&o))\n")
 	g.Outdent()
 	g.Printf("}\n\n")
 
@@ -623,16 +582,9 @@ func (g *goGen) genType(sym *symbol) {
 		g.Indent()
 		g.Printf("arr := (*%[1]s)(unsafe.Pointer(self))\n", sym.gofmt())
 		g.Printf("elt := (*arr)[i]\n")
-		if !esym.isBasic() {
-			g.Printf("cgopy_incref(unsafe.Pointer(&elt))\n")
-			g.Printf("return (%[1]s)(unsafe.Pointer(&elt))\n", esym.cgotypename())
-		} else {
-			if esym.isNamed() {
-				g.Printf("return %[1]s(elt)\n", esym.cgotypename())
-			} else {
-				g.Printf("return elt\n")
-			}
-		}
+		g.Printf("cgopy_incref(unsafe.Pointer(&elt))\n")
+		g.Printf("return (%[1]s)(unsafe.Pointer(&elt))\n", esym.cgotypename())
+
 		g.Outdent()
 		g.Printf("}\n\n")
 
@@ -646,15 +598,8 @@ func (g *goGen) genType(sym *symbol) {
 		g.Indent()
 		g.Printf("arr := (*%[1]s)(unsafe.Pointer(self))\n", sym.gofmt())
 		g.Printf("(*arr)[i] = ")
-		if !esym.isBasic() {
-			g.Printf("*(*%[1]s)(unsafe.Pointer(v))\n", esym.gofmt())
-		} else {
-			if esym.isNamed() {
-				g.Printf("%[1]s(v)\n", esym.gofmt())
-			} else {
-				g.Printf("v\n")
-			}
-		}
+		g.Printf("*(*%[1]s)(unsafe.Pointer(&v))\n", esym.gofmt())
+
 		g.Outdent()
 		g.Printf("}\n\n")
 	}
@@ -678,15 +623,7 @@ func (g *goGen) genType(sym *symbol) {
 		g.Indent()
 		g.Printf("slice := (*%[1]s)(unsafe.Pointer(self))\n", sym.gofmt())
 		g.Printf("*slice = append(*slice, ")
-		if !esym.isBasic() {
-			g.Printf("*(*%[1]s)(unsafe.Pointer(v))", esym.gofmt())
-		} else {
-			if esym.isNamed() {
-				g.Printf("%[1]s(v)", esym.gofmt())
-			} else {
-				g.Printf("v")
-			}
-		}
+		g.Printf("*(*%[1]s)(unsafe.Pointer(v))", esym.gofmt())
 		g.Printf(")\n")
 		g.Outdent()
 		g.Printf("}\n\n")
@@ -767,27 +704,18 @@ func (g *goGen) genTypeTPCall(sym *symbol) {
 			}
 			arg := params.At(i)
 			sarg := g.pkg.syms.symtype(arg.Type())
-			if sarg.isBasic() {
-				g.Printf("%sarg%03d", comma, i)
-			} else {
-				g.Printf(
-					"%s*(*%s)(unsafe.Pointer(arg%03d))",
-					comma,
-					sarg.gofmt(),
-					i,
-				)
-			}
+			g.Printf(
+				"%s*(*%s)(unsafe.Pointer(arg%03d))",
+				comma,
+				sarg.gofmt(),
+				i,
+			)
 		}
 	}
 	g.Printf(")\n")
 	if res != nil && res.Len() > 0 {
 		for i := 0; i < res.Len(); i++ {
-			ret := res.At(i)
-			sret := g.pkg.syms.symtype(ret.Type())
-			if !needWrapType(sret.GoType()) {
-				continue
-			}
-			g.Printf("cgopy_incref(unsafe.Pointer(&arg%03d))", i)
+			g.Printf("cgopy_incref(unsafe.Pointer(&arg%03d))\n", i)
 		}
 
 		g.Printf("return ")
@@ -797,13 +725,7 @@ func (g *goGen) genTypeTPCall(sym *symbol) {
 			}
 			ret := res.At(i)
 			sret := g.pkg.syms.symtype(ret.Type())
-			if needWrapType(ret.Type()) {
-				g.Printf("%s(unsafe.Pointer(&", sret.cgotypename())
-			}
-			g.Printf("res%03d", i)
-			if needWrapType(ret.Type()) {
-				g.Printf("))")
-			}
+			g.Printf("%s(unsafe.Pointer(&res%03d))", sret.cgotypename())
 		}
 		g.Printf("\n")
 	}
@@ -887,17 +809,10 @@ func (g *goGen) genTypeMethods(sym *symbol) {
 				g.Printf(" := ")
 			}
 		}
-		if sym.isBasic() {
-			g.Printf("(*%s)(unsafe.Pointer(&self)).%s(",
-				sym.gofmt(),
-				msym.goname,
-			)
-		} else {
-			g.Printf("(*%s)(unsafe.Pointer(self)).%s(",
-				sym.gofmt(),
-				msym.goname,
-			)
-		}
+		g.Printf("(*%s)(unsafe.Pointer(self)).%s(",
+			sym.gofmt(),
+			msym.goname,
+		)
 
 		if params != nil {
 			for i := 0; i < params.Len(); i++ {
@@ -905,14 +820,10 @@ func (g *goGen) genTypeMethods(sym *symbol) {
 					g.Printf(", ")
 				}
 				sarg := g.pkg.syms.symtype(params.At(i).Type())
-				if needWrapType(sarg.GoType()) {
-					g.Printf("*(*%s)(unsafe.Pointer(arg%03d))",
-						sarg.gofmt(),
-						i,
-					)
-				} else {
-					g.Printf("arg%03d", i)
-				}
+				g.Printf("*(*%s)(unsafe.Pointer(arg%03d))",
+					sarg.gofmt(),
+					i,
+				)
 			}
 		}
 		g.Printf(")\n")
@@ -929,16 +840,11 @@ func (g *goGen) genTypeMethods(sym *symbol) {
 				g.Printf(", ")
 			}
 			sret := g.pkg.syms.symtype(res.At(i).Type())
-			if needWrapType(sret.GoType()) {
-				g.Printf(
-					"%s(unsafe.Pointer(&",
-					sret.cgoname,
-				)
-			}
-			g.Printf("res%03d", i)
-			if needWrapType(sret.GoType()) {
-				g.Printf("))")
-			}
+			g.Printf(
+				"%s(unsafe.Pointer(&res%03d))",
+				sret.cgoname,
+				i,
+			)
 		}
 		g.Printf("\n")
 
@@ -949,17 +855,39 @@ func (g *goGen) genTypeMethods(sym *symbol) {
 
 func (g *goGen) genPreamble() {
 	n := g.pkg.pkg.Name()
-	pkgimport := fmt.Sprintf("%q", g.pkg.pkg.Path())
-	if g.pkg.n == 0 {
-		pkgimport = fmt.Sprintf("_ %q", g.pkg.pkg.Path())
-	}
 
 	pkgcfg, err := getPkgConfig(g.lang)
 	if err != nil {
 		panic(err)
 	}
 
-	g.Printf(goPreamble, n, pkgcfg, pkgimport)
+	pkgimport := fmt.Sprintf("%q", g.pkg.pkg.Path())
+	if g.pkg.n == 0 {
+		pkgimport = fmt.Sprintf("_ %q", g.pkg.pkg.Path())
+	}
+
+	builtins := []string{}
+	for _, name := range []string{
+		"bool",
+		"byte",
+		"int", "int8", "int16", "int32", "int64",
+		"uint", "uint8", "uint16", "uint32", "uint64",
+		"float32", "float64",
+		"complex64", "complex128",
+		"string", "rune",
+		"interface",
+	} {
+		builtins = append(builtins,
+			fmt.Sprintf("//export cgo_type_%[1]s", name),
+			fmt.Sprintf("type cgo_type_%[1]s unsafe.Pointer", name),
+			"",
+		)
+	}
+
+	g.Printf(goPreamble,
+		n, pkgcfg, pkgimport,
+		strings.Join(builtins, "\n"),
+	)
 }
 
 func (g *goGen) tupleString(tuple []*Var) string {
diff --git a/bind/symtab.go b/bind/symtab.go
index 119b959..387ff3a 100644
--- a/bind/symtab.go
+++ b/bind/symtab.go
@@ -154,25 +154,6 @@ func (s symbol) GoType() types.Type {
 }
 
 func (s symbol) cgotypename() string {
-	typ := s.gotyp
-	switch typ := typ.(type) {
-	case *types.Basic:
-		n := typ.Name()
-		if strings.HasPrefix(n, "untyped ") {
-			n = string(n[len("untyped "):])
-		}
-		return n
-	case *types.Named:
-		obj := s.goobj
-		switch typ.Underlying().(type) {
-		case *types.Struct:
-			return s.cgoname
-		case *types.Interface:
-			if obj.Name() == "error" {
-				return "error"
-			}
-		}
-	}
 	return s.cgoname
 }
 
@@ -516,12 +497,13 @@ func (sym *symtab) addMapType(pkg *types.Package, obj types.Object, t types.Type
 		cgoname: "cgo_type_" + id,
 		cpyname: "cpy_type_" + id,
 		pyfmt:   "O&",
-		pybuf:   elt.pybuf,//fmt.Sprintf("%d%s", typ.Len(), elt.pybuf),
+		pybuf:   elt.pybuf, //fmt.Sprintf("%d%s", typ.Len(), elt.pybuf),
 		pysig:   "object",
 		c2py:    "cgopy_cnv_c2py_" + id,
 		py2c:    "cgopy_cnv_py2c_" + id,
 		pychk:   fmt.Sprintf("cpy_func_%[1]s_check(%%s)", id),
-	}}
+	}
+}
 
 func (sym *symtab) addSliceType(pkg *types.Package, obj types.Object, t types.Type, kind symkind, id, n string) {
 	fn := sym.typename(t, nil)
@@ -732,7 +714,7 @@ func init() {
 			gotyp:   look("bool").Type(),
 			kind:    skType | skBasic,
 			goname:  "bool",
-			cgoname: "GoUint8",
+			cgoname: "cgo_type_bool",
 			cpyname: "GoUint8",
 			pyfmt:   "O&",
 			pybuf:   "?",
@@ -748,9 +730,9 @@ func init() {
 			gotyp:   look("byte").Type(),
 			kind:    skType | skBasic,
 			goname:  "byte",
-			cpyname: "uint8_t",
-			cgoname: "GoUint8",
-			pyfmt:   "b",
+			cgoname: "cgo_type_byte",
+			cpyname: "GoUint8",
+			pyfmt:   "O&",
 			pybuf:   "B",
 			pysig:   "int", // FIXME(sbinet) py2/py3
 			pychk:   "PyByte_Check(%s)",
@@ -763,8 +745,8 @@ func init() {
 			kind:    skType | skBasic,
 			goname:  "int",
 			cpyname: "int",
-			cgoname: "GoInt",
-			pyfmt:   "i",
+			cgoname: "cgo_type_int",
+			pyfmt:   "O&",
 			pybuf:   "i",
 			pysig:   "int",
 			c2py:    "cgopy_cnv_c2py_int",
@@ -779,8 +761,8 @@ func init() {
 			kind:    skType | skBasic,
 			goname:  "int8",
 			cpyname: "int8_t",
-			cgoname: "GoInt8",
-			pyfmt:   "b",
+			cgoname: "cgo_type_int8",
+			pyfmt:   "O&",
 			pybuf:   "b",
 			pysig:   "int",
 			c2py:    "cgopy_cnv_c2py_int8",
@@ -795,8 +777,8 @@ func init() {
 			kind:    skType | skBasic,
 			goname:  "int16",
 			cpyname: "int16_t",
-			cgoname: "GoInt16",
-			pyfmt:   "h",
+			cgoname: "cgo_type_int16",
+			pyfmt:   "O&",
 			pybuf:   "h",
 			pysig:   "int",
 			c2py:    "cgopy_cnv_c2py_int16",
@@ -811,8 +793,8 @@ func init() {
 			kind:    skType | skBasic,
 			goname:  "int32",
 			cpyname: "int32_t",
-			cgoname: "GoInt32",
-			pyfmt:   "i",
+			cgoname: "cgo_type_int32",
+			pyfmt:   "O&",
 			pybuf:   "i",
 			pysig:   "int",
 			c2py:    "cgopy_cnv_c2py_int32",
@@ -827,8 +809,8 @@ func init() {
 			kind:    skType | skBasic,
 			goname:  "int64",
 			cpyname: "int64_t",
-			cgoname: "GoInt64",
-			pyfmt:   "k",
+			cgoname: "cgo_type_int64",
+			pyfmt:   "O&",
 			pybuf:   "q",
 			pysig:   "long",
 			c2py:    "cgopy_cnv_c2py_int64",
@@ -843,8 +825,8 @@ func init() {
 			kind:    skType | skBasic,
 			goname:  "uint",
 			cpyname: "unsigned int",
-			cgoname: "GoUint",
-			pyfmt:   "I",
+			cgoname: "cgo_type_uint",
+			pyfmt:   "O&",
 			pybuf:   "I",
 			pysig:   "int",
 			c2py:    "cgopy_cnv_c2py_uint",
@@ -859,8 +841,8 @@ func init() {
 			kind:    skType | skBasic,
 			goname:  "uint8",
 			cpyname: "uint8_t",
-			cgoname: "GoUint8",
-			pyfmt:   "B",
+			cgoname: "cgo_type_uint8",
+			pyfmt:   "O&",
 			pybuf:   "B",
 			pysig:   "int",
 			c2py:    "cgopy_cnv_c2py_uint8",
@@ -875,8 +857,8 @@ func init() {
 			kind:    skType | skBasic,
 			goname:  "uint16",
 			cpyname: "uint16_t",
-			cgoname: "GoUint16",
-			pyfmt:   "H",
+			cgoname: "cgo_type_uint16",
+			pyfmt:   "O&",
 			pybuf:   "H",
 			pysig:   "int",
 			c2py:    "cgopy_cnv_c2py_uint16",
@@ -891,8 +873,8 @@ func init() {
 			kind:    skType | skBasic,
 			goname:  "uint32",
 			cpyname: "uint32_t",
-			cgoname: "GoUint32",
-			pyfmt:   "I",
+			cgoname: "cgo_type_uint32",
+			pyfmt:   "O&",
 			pybuf:   "I",
 			pysig:   "long",
 			c2py:    "cgopy_cnv_c2py_uint32",
@@ -907,8 +889,8 @@ func init() {
 			kind:    skType | skBasic,
 			goname:  "uint64",
 			cpyname: "uint64_t",
-			cgoname: "GoUint64",
-			pyfmt:   "K",
+			cgoname: "cgo_type_uint64",
+			pyfmt:   "O&",
 			pybuf:   "Q",
 			pysig:   "long",
 			c2py:    "cgopy_cnv_c2py_uint64",
@@ -923,8 +905,8 @@ func init() {
 			kind:    skType | skBasic,
 			goname:  "float32",
 			cpyname: "float",
-			cgoname: "GoFloat32",
-			pyfmt:   "f",
+			cgoname: "cgo_type_float32",
+			pyfmt:   "O&",
 			pybuf:   "f",
 			pysig:   "float",
 			c2py:    "cgopy_cnv_c2py_float32",
@@ -939,8 +921,8 @@ func init() {
 			kind:    skType | skBasic,
 			goname:  "float64",
 			cpyname: "double",
-			cgoname: "GoFloat64",
-			pyfmt:   "d",
+			cgoname: "cgo_type_float64",
+			pyfmt:   "O&",
 			pybuf:   "d",
 			pysig:   "float",
 			c2py:    "cgopy_cnv_c2py_float64",
@@ -955,8 +937,8 @@ func init() {
 			kind:    skType | skBasic,
 			goname:  "complex64",
 			cpyname: "float complex",
-			cgoname: "GoComplex64",
-			pyfmt:   "D",
+			cgoname: "cgo_type_complex64",
+			pyfmt:   "O&",
 			pybuf:   "ff",
 			pysig:   "complex",
 			c2py:    "cgopy_cnv_c2py_complex64",
@@ -971,8 +953,8 @@ func init() {
 			kind:    skType | skBasic,
 			goname:  "complex128",
 			cpyname: "double complex",
-			cgoname: "GoComplex128",
-			pyfmt:   "D",
+			cgoname: "cgo_type_complex128",
+			pyfmt:   "O&",
 			pybuf:   "dd",
 			pysig:   "complex",
 			c2py:    "cgopy_cnv_c2py_complex128",
@@ -986,8 +968,8 @@ func init() {
 			gotyp:   look("string").Type(),
 			kind:    skType | skBasic,
 			goname:  "string",
-			cpyname: "GoString",
-			cgoname: "GoString",
+			cpyname: "cgo_type_string",
+			cgoname: "cgo_type_string",
 			pyfmt:   "O&",
 			pybuf:   "s",
 			pysig:   "str",
@@ -1003,7 +985,7 @@ func init() {
 			kind:    skType | skBasic,
 			goname:  "rune",
 			cpyname: "GoRune",
-			cgoname: "GoRune",
+			cgoname: "cgo_type_rune",
 			pyfmt:   "O&",
 			pybuf:   "p",
 			pysig:   "str",
@@ -1018,7 +1000,7 @@ func init() {
 			gotyp:   look("error").Type(),
 			kind:    skType | skInterface,
 			goname:  "error",
-			cgoname: "GoInterface",
+			cgoname: "cgo_type_interface",
 			cpyname: "GoInterface",
 			pyfmt:   "O&",
 			pybuf:   "PP",
@@ -1036,8 +1018,8 @@ func init() {
 			kind:    skType | skBasic,
 			goname:  "int",
 			cpyname: "int64_t",
-			cgoname: "GoInt",
-			pyfmt:   "k",
+			cgoname: "cgo_type_int",
+			pyfmt:   "O&",
 			pybuf:   "q",
 			pysig:   "int",
 			c2py:    "cgopy_cnv_c2py_int",
@@ -1051,8 +1033,8 @@ func init() {
 			kind:    skType | skBasic,
 			goname:  "uint",
 			cpyname: "uint64_t",
-			cgoname: "GoUint",
-			pyfmt:   "K",
+			cgoname: "cgo_type_uint",
+			pyfmt:   "O&",
 			pybuf:   "Q",
 			pysig:   "int",
 			c2py:    "cgopy_cnv_c2py_uint",
diff --git a/bind/types.go b/bind/types.go
index 21db5b6..bd178de 100644
--- a/bind/types.go
+++ b/bind/types.go
@@ -19,36 +19,3 @@ type Type interface {
 	Object
 	GoType() types.Type
 }
-
-func needWrapType(typ types.Type) bool {
-	switch typ := typ.(type) {
-	case *types.Basic:
-		return false
-	case *types.Struct:
-		return true
-	case *types.Named:
-		switch ut := typ.Underlying().(type) {
-		case *types.Basic:
-			return false
-		default:
-			return needWrapType(ut)
-		}
-	case *types.Array:
-		return true
-	case *types.Map:
-		return true
-	case *types.Slice:
-		return true
-	case *types.Interface:
-		wrap := true
-		if typ.Underlying() == universe.syms["error"].GoType().Underlying() {
-			wrap = false
-		}
-		return wrap
-	case *types.Signature:
-		return true
-	case *types.Pointer:
-		return needWrapType(typ.Elem())
-	}
-	return false
-}
diff --git a/bind/vars.go b/bind/vars.go
index 502507d..6f25d34 100644
--- a/bind/vars.go
+++ b/bind/vars.go
@@ -125,8 +125,3 @@ func (v *Var) genFuncPreamble(g *printer) {
 func (v *Var) getFuncArg() string {
 	return "c_" + v.Name()
 }
-
-func (v *Var) needWrap() bool {
-	typ := v.GoType()
-	return needWrapType(typ)
-}