diff --git a/include/proto/channel.h b/include/proto/channel.h
index d13169bd6..e2424f147 100644
--- a/include/proto/channel.h
+++ b/include/proto/channel.h
@@ -103,11 +103,12 @@ static inline unsigned int channel_is_empty(struct channel *c)
 	return !(c->buf->o | (long)c->pipe);
 }
 
-/* Returns non-zero if the buffer input has all of its reserve available. This
- * is used to decide when a request or response may be parsed when some data
- * from a previous exchange might still be present.
+/* Returns non-zero if the channel is rewritable, which means that the buffer
+ * it is attached to has at least <maxrewrite> bytes immediately available.
+ * This is used to decide when a request or response may be parsed when some
+ * data from a previous exchange might still be present.
  */
-static inline int channel_reserved(const struct channel *chn)
+static inline int channel_is_rewritable(const struct channel *chn)
 {
 	int rem = chn->buf->size;
 
diff --git a/src/proto_http.c b/src/proto_http.c
index 4b14b88fa..e14b1d69c 100644
--- a/src/proto_http.c
+++ b/src/proto_http.c
@@ -2502,7 +2502,7 @@ int http_wait_for_request(struct session *s, struct channel *req, int an_bit)
 	 */
 	if (buffer_not_empty(req->buf) && msg->msg_state < HTTP_MSG_ERROR) {
 		if (txn->flags & TX_NOT_FIRST) {
-			if (unlikely(!channel_reserved(req))) {
+			if (unlikely(!channel_is_rewritable(req))) {
 				if (req->flags & (CF_SHUTW|CF_SHUTW_NOW|CF_WRITE_ERROR|CF_WRITE_TIMEOUT))
 					goto failed_keep_alive;
 				/* some data has still not left the buffer, wake us once that's done */
@@ -2524,7 +2524,7 @@ int http_wait_for_request(struct session *s, struct channel *req, int an_bit)
 		 * keep-alive requests.
 		 */
 		if ((txn->flags & TX_NOT_FIRST) &&
-		    unlikely(!channel_reserved(s->rep) ||
+		    unlikely(!channel_is_rewritable(s->rep) ||
 			     bi_end(s->rep->buf) < b_ptr(s->rep->buf, txn->rsp.next) ||
 			     bi_end(s->rep->buf) > s->rep->buf->data + s->rep->buf->size - global.tune.maxrewrite)) {
 			if (s->rep->buf->o) {
@@ -5673,7 +5673,7 @@ int http_wait_for_response(struct session *s, struct channel *rep, int an_bit)
 	 * data later, which is much more complicated.
 	 */
 	if (buffer_not_empty(rep->buf) && msg->msg_state < HTTP_MSG_ERROR) {
-		if (unlikely(!channel_reserved(rep))) {
+		if (unlikely(!channel_is_rewritable(rep))) {
 			/* some data has still not left the buffer, wake us once that's done */
 			if (rep->flags & (CF_SHUTW|CF_SHUTW_NOW|CF_WRITE_ERROR|CF_WRITE_TIMEOUT))
 				goto abort_response;