diff --git a/channels/chan_sip.c b/channels/chan_sip.c
index fc176db02210d68b366f173f23e703878f5a51ea..6c7478ceb1dd54a9f90eb704ebdd44b98526b641 100644
--- a/channels/chan_sip.c
+++ b/channels/chan_sip.c
@@ -8308,15 +8308,15 @@ static void copy_request(struct sip_request *dst, const struct sip_request *src)
 	if (!dst->data && !(dst->data = ast_str_create(src->data->used)))
 		return;
 	else if (dst->data->len < src->data->used)
-		ast_str_make_space(&dst->data, src->data->used);
+		ast_str_make_space(&dst->data, src->data->used + 1); /* Account for null terminator needed */
 		
-	memcpy(dst->data->str, src->data->str, src->data->used);
+	ast_copy_string(dst->data->str, src->data->str, dst->data->len);
 	dst->data->used = src->data->used;
 	offset = ((void *)dst->data->str) - ((void *)src->data->str);
 	/* Now fix pointer arithmetic */
-	for (x=0; x < src->headers; x++)
+	for (x = 0; x < src->headers; x++)
 		dst->header[x] += offset;
-	for (x=0; x < src->lines; x++)
+	for (x = 0; x < src->lines; x++)
 		dst->line[x] += offset;
 	/* On some occasions this function is called without parse_request being called first so lets not create an invalid pointer */
 	if (src->rlPart1)
diff --git a/include/asterisk/strings.h b/include/asterisk/strings.h
index 226c7bb67ef7cdf4875a6381ea8d352c0643261d..fbff083abd3fb275d1c4f7fc2de9472d39910d2d 100644
--- a/include/asterisk/strings.h
+++ b/include/asterisk/strings.h
@@ -326,7 +326,7 @@ int ast_get_timeval(const char *src, struct timeval *tv, struct timeval _default
  */
 struct ast_str {
 	size_t len;	/*!< The current maximum length of the string */
-	size_t used;	/*!< Amount of space used */
+	size_t used;	/*!< Amount of space used. Does not include string's null terminator */
 	struct ast_threadstorage *ts;	/*!< What kind of storage is this ? */
 #define DS_MALLOC	((struct ast_threadstorage *)1)
 #define DS_ALLOCA	((struct ast_threadstorage *)2)