diff -r d51d6f1f9db8 Include/pymacro.h
--- a/Include/pymacro.h	Mon Jan 20 08:13:31 2014 -0800
+++ b/Include/pymacro.h	Tue Jan 21 00:04:31 2014 -0600
@@ -47,6 +47,7 @@
 
 
 /* Define macros for inline documentation. */
+#define PyDoc_SIZEDVAR(name, size) static char name[size]
 #define PyDoc_VAR(name) static char name[]
 #define PyDoc_STRVAR(name,str) PyDoc_VAR(name) = PyDoc_STR(str)
 #ifdef WITH_DOC_STRINGS
diff -r d51d6f1f9db8 Tools/clinic/clinic.py
--- a/Tools/clinic/clinic.py	Mon Jan 20 08:13:31 2014 -0800
+++ b/Tools/clinic/clinic.py	Tue Jan 21 00:04:31 2014 -0600
@@ -464,7 +464,7 @@
 
 docstring_prototype
 
-PyDoc_VAR({c_basename}__doc__);
+PyDoc_SIZEDVAR({c_basename}__doc__, {docstring_size});
 __________________________________________________
 
 docstring_definition
@@ -959,6 +959,7 @@
         template_dict['methoddef_name'] = methoddef_name
 
         template_dict['docstring'] = self.docstring_for_c_string(f)
+        template_dict['docstring_size'] = len(f.docstring)
 
         positional = has_option_groups =  False