diff --git a/Python/sysmodule.c b/Python/sysmodule.c
index ea1388b..2dbe283 100644
--- a/Python/sysmodule.c
+++ b/Python/sysmodule.c
@@ -1137,41 +1137,38 @@
 #elif PY_RELEASE_LEVEL == PY_RELEASE_LEVEL_FINAL
 	s = "final";
 #endif
-	PyDict_SetItemString(sysdict, "version_info",
-			     v = Py_BuildValue("iiisi", PY_MAJOR_VERSION,
+
+#define SET_SYS_FROM_STRING(key, value)			\
+	v = value;					\
+	if (v != NULL)					\
+		PyDict_SetItemString(sysdict, key, v);	\
+	Py_XDECREF(v)
+
+	SET_SYS_FROM_STRING("version_info",
+			    Py_BuildValue("iiisi", PY_MAJOR_VERSION,
 					       PY_MINOR_VERSION,
 					       PY_MICRO_VERSION, s,
 					       PY_RELEASE_SERIAL));
-	Py_XDECREF(v);
-	PyDict_SetItemString(sysdict, "api_version",
-			     v = PyInt_FromLong(PYTHON_API_VERSION));
-	Py_XDECREF(v);
-	PyDict_SetItemString(sysdict, "copyright",
-			     v = PyString_FromString(Py_GetCopyright()));
-	Py_XDECREF(v);
-	PyDict_SetItemString(sysdict, "platform",
-			     v = PyString_FromString(Py_GetPlatform()));
-	Py_XDECREF(v);
-	PyDict_SetItemString(sysdict, "executable",
-			     v = PyString_FromString(Py_GetProgramFullPath()));
-	Py_XDECREF(v);
-	PyDict_SetItemString(sysdict, "prefix",
-			     v = PyString_FromString(Py_GetPrefix()));
-	Py_XDECREF(v);
-	PyDict_SetItemString(sysdict, "exec_prefix",
-		   v = PyString_FromString(Py_GetExecPrefix()));
-	Py_XDECREF(v);
-	PyDict_SetItemString(sysdict, "maxint",
-			     v = PyInt_FromLong(PyInt_GetMax()));
-	Py_XDECREF(v);
+	SET_SYS_FROM_STRING("api_version",
+			    PyInt_FromLong(PYTHON_API_VERSION));
+	SET_SYS_FROM_STRING("copyright",
+			    PyString_FromString(Py_GetCopyright()));
+	SET_SYS_FROM_STRING("platform",
+			    PyString_FromString(Py_GetPlatform()));
+	SET_SYS_FROM_STRING("executable",
+			    PyString_FromString(Py_GetProgramFullPath()));
+	SET_SYS_FROM_STRING("prefix",
+			    PyString_FromString(Py_GetPrefix()));
+	SET_SYS_FROM_STRING("exec_prefix",
+		   	    PyString_FromString(Py_GetExecPrefix()));
+	SET_SYS_FROM_STRING("maxint",
+			    PyInt_FromLong(PyInt_GetMax()));
 #ifdef Py_USING_UNICODE
-	PyDict_SetItemString(sysdict, "maxunicode",
-			     v = PyInt_FromLong(PyUnicode_GetMax()));
-	Py_XDECREF(v);
+	SET_SYS_FROM_STRING("maxunicode",
+			    PyInt_FromLong(PyUnicode_GetMax()));
 #endif
-	PyDict_SetItemString(sysdict, "builtin_module_names",
-		   v = list_builtin_module_names());
-	Py_XDECREF(v);
+	SET_SYS_FROM_STRING("builtin_module_names",
+			    list_builtin_module_names());
 	{
 		/* Assumes that longs are at least 2 bytes long.
 		   Should be safe! */
@@ -1183,18 +1180,16 @@
 			value = "big";
 		else
 			value = "little";
-		PyDict_SetItemString(sysdict, "byteorder",
-				     v = PyString_FromString(value));
-		Py_XDECREF(v);
+		SET_SYS_FROM_STRING("byteorder",
+				    PyString_FromString(value));
 	}
 #ifdef MS_COREDLL
-	PyDict_SetItemString(sysdict, "dllhandle",
-			     v = PyLong_FromVoidPtr(PyWin_DLLhModule));
-	Py_XDECREF(v);
-	PyDict_SetItemString(sysdict, "winver",
-			     v = PyString_FromString(PyWin_DLLVersionString));
-	Py_XDECREF(v);
+	SET_SYS_FROM_STRING("dllhandle",
+			    PyLong_FromVoidPtr(PyWin_DLLhModule));
+	SET_SYS_FROM_STRING("winver",
+			    PyString_FromString(PyWin_DLLVersionString));
 #endif
+#undef SET_SYS_FROM_STRING
 	if (warnoptions == NULL) {
 		warnoptions = PyList_New(0);
 	}