diff --git a/windows/Makefile b/windows/Makefile
index e3085ff23b..44029c028f 100644
--- a/windows/Makefile
+++ b/windows/Makefile
@@ -34,6 +34,7 @@ SRC_C = \
 	unix/main.c \
 	unix/file.c \
 	unix/input.c \
+	unix/modos.c \
 	unix/modtime.c \
 	unix/gccollect.c \
 	realpath.c \
diff --git a/windows/mpconfigport.h b/windows/mpconfigport.h
index 852ca3f5fb..9725c3dfe5 100644
--- a/windows/mpconfigport.h
+++ b/windows/mpconfigport.h
@@ -50,17 +50,24 @@
 #define MICROPY_PY_BUILTINS_FROZENSET (1)
 #define MICROPY_PY_SYS_EXIT         (1)
 #define MICROPY_PY_SYS_PLATFORM     "win32"
+#define MICROPY_PY_SYS_MAXSIZE      (1)
 #define MICROPY_PY_SYS_STDFILES     (1)
 #define MICROPY_PY_CMATH            (1)
 #define MICROPY_PY_IO_FILEIO        (1)
 #define MICROPY_PY_GC_COLLECT_RETVAL (1)
+
 #define MICROPY_PY_UCTYPES          (1)
 #define MICROPY_PY_ZLIBD            (1)
+#define MICROPY_PY_UJSON            (1)
+
 #define MICROPY_ERROR_REPORTING     (MICROPY_ERROR_REPORTING_DETAILED)
 #ifdef _MSC_VER
 #define MICROPY_GCREGS_SETJMP       (1)
 #endif
 
+#define MICROPY_ENABLE_EMERGENCY_EXCEPTION_BUF   (1)
+#define MICROPY_EMERGENCY_EXCEPTION_BUF_SIZE     (128)
+
 #define MICROPY_PORT_INIT_FUNC      init()
 #define MICROPY_PORT_DEINIT_FUNC    deinit()
 
@@ -84,13 +91,17 @@ typedef unsigned int mp_uint_t; // must be pointer size
 typedef void *machine_ptr_t; // must be of pointer size
 typedef const void *machine_const_ptr_t; // must be of pointer size
 
+extern const struct _mp_obj_fun_builtin_t mp_builtin_input_obj;
 extern const struct _mp_obj_fun_builtin_t mp_builtin_open_obj;
 #define MICROPY_PORT_BUILTINS \
+    { MP_OBJ_NEW_QSTR(MP_QSTR_input), (mp_obj_t)&mp_builtin_input_obj }, \
     { MP_OBJ_NEW_QSTR(MP_QSTR_open), (mp_obj_t)&mp_builtin_open_obj },
 
+extern const struct _mp_obj_module_t mp_module_os;
 extern const struct _mp_obj_module_t mp_module_time;
 #define MICROPY_PORT_BUILTIN_MODULES \
     { MP_OBJ_NEW_QSTR(MP_QSTR_time), (mp_obj_t)&mp_module_time }, \
+    { MP_OBJ_NEW_QSTR(MP_QSTR__os), (mp_obj_t)&mp_module_os }, \
 
 // We need to provide a declaration/definition of alloca()
 #include <malloc.h>
@@ -113,8 +124,13 @@ void msec_sleep(double msec);
 
 // CL specific overrides from mpconfig
 
-#define NORETURN                   __declspec(noreturn)
-#define MICROPY_PORT_CONSTANTS     { "dummy", 0 } //can't have zero-sized array
+#define NORETURN                    __declspec(noreturn)
+#define MICROPY_PORT_CONSTANTS      { "dummy", 0 } //can't have zero-sized array
+#ifdef _WIN64
+#define MP_SSIZE_MAX                _I64_MAX
+#else
+#define MP_SSIZE_MAX                _I32_MAX
+#endif
 
 
 // CL specific definitions
diff --git a/windows/msvc/sources.props b/windows/msvc/sources.props
index b48277ff29..364f36b044 100644
--- a/windows/msvc/sources.props
+++ b/windows/msvc/sources.props
@@ -6,7 +6,7 @@
   <ItemGroup>
     <ClCompile Include="$(PyBaseDir)py\*.c" />
     <ClCompile Include="$(PyBaseDir)extmod\*.c" />
-    <ClCompile Include="$(PyBaseDir)unix\*.c" Exclude="$(PyBaseDir)unix\modffi.c;$(PyBaseDir)unix\modsocket.c;$(PyBaseDir)unix\modtermios.c;$(PyBaseDir)unix\seg_helpers.c" />
+    <ClCompile Include="$(PyBaseDir)unix\*.c" Exclude="$(PyBaseDir)unix\alloc.c;$(PyBaseDir)unix\modffi.c;$(PyBaseDir)unix\modsocket.c;$(PyBaseDir)unix\modtermios.c;$(PyBaseDir)unix\seg_helpers.c" />
     <ClCompile Include="$(PyBaseDir)windows\*.c" />
     <ClCompile Include="$(PyBaseDir)windows\msvc\*.c" />
   </ItemGroup>