--- contrib/python/aiohttp/aiohttp/_http_parser.pyx	(index)
+++ contrib/python/aiohttp/aiohttp/_http_parser.pyx	(working tree)
@@ -393,7 +393,7 @@ cdef class HttpParser:
             self._has_value = False
             self._raw_headers.append((raw_name, raw_value))
 
-    cdef _on_header_field(self, char* at, size_t length):
+    cdef _on_header_field(self, const char* at, size_t length):
         cdef Py_ssize_t size
         cdef char *buf
         if self._has_value:
@@ -404,7 +404,7 @@ cdef class HttpParser:
         buf = PyByteArray_AsString(self._raw_name)
         memcpy(buf + size, at, length)
 
-    cdef _on_header_value(self, char* at, size_t length):
+    cdef _on_header_value(self, const char* at, size_t length):
         cdef Py_ssize_t size
         cdef char *buf