diff --git a/include/common/buffer.h b/include/common/buffer.h
index fd2957579..52565dd9b 100644
--- a/include/common/buffer.h
+++ b/include/common/buffer.h
@@ -395,6 +395,20 @@ static inline void b_reset(struct buffer *buf)
 	buf->p = buf->data;
 }
 
+/* Allocates a buffer and replaces *buf with this buffer. No control is made
+ * to check if *buf already pointed to another buffer. The allocated buffer
+ * is returned, or NULL in case no memory is available.
+ */
+static inline struct buffer *b_alloc(struct buffer **buf)
+{
+	*buf = pool_alloc_dirty(pool2_buffer);
+	if (likely(*buf)) {
+		(*buf)->size = pool2_buffer->size - sizeof(struct buffer);
+		b_reset(*buf);
+	}
+	return *buf;
+}
+
 #endif /* _COMMON_BUFFER_H */
 
 /*
diff --git a/src/compression.c b/src/compression.c
index b6c4ae201..db2209adc 100644
--- a/src/compression.c
+++ b/src/compression.c
@@ -137,8 +137,6 @@ int http_compression_buffer_init(struct session *s, struct buffer *in, struct bu
 	/* We start by copying the current buffer's pending outgoing data into
 	 * a new temporary buffer that we initialize with a new empty chunk.
 	 */
-
-	out->size = global.tune.bufsize;
 	b_reset(out);
 
 	if (in->o > 0) {
diff --git a/src/peers.c b/src/peers.c
index 9ff177354..a5dff87e6 100644
--- a/src/peers.c
+++ b/src/peers.c
@@ -1237,11 +1237,9 @@ static struct session *peer_session_create(struct peer *peer, struct peer_sessio
 	if ((s->req = pool_alloc2(pool2_channel)) == NULL)
 		goto out_fail_req; /* no memory */
 
-	if ((s->req->buf = pool_alloc2(pool2_buffer)) == NULL)
+	if (unlikely(b_alloc(&s->req->buf) == NULL))
 		goto out_fail_req_buf; /* no memory */
 
-	s->req->buf->size = global.tune.bufsize;
-	b_reset(s->req->buf);
 	channel_init(s->req);
 	s->req->prod = &s->si[0];
 	s->req->cons = &s->si[1];
@@ -1264,11 +1262,9 @@ static struct session *peer_session_create(struct peer *peer, struct peer_sessio
 	if ((s->rep = pool_alloc2(pool2_channel)) == NULL)
 		goto out_fail_rep; /* no memory */
 
-	if ((s->rep->buf = pool_alloc2(pool2_buffer)) == NULL)
+	if (unlikely(b_alloc(&s->rep->buf) == NULL))
 		goto out_fail_rep_buf; /* no memory */
 
-	s->rep->buf->size = global.tune.bufsize;
-	b_reset(s->rep->buf);
 	channel_init(s->rep);
 	s->rep->prod = &s->si[1];
 	s->rep->cons = &s->si[0];
diff --git a/src/proto_http.c b/src/proto_http.c
index 3fffc5bb4..ee1a812c8 100644
--- a/src/proto_http.c
+++ b/src/proto_http.c
@@ -6572,8 +6572,7 @@ int http_response_forward_body(struct session *s, struct channel *res, int an_bi
 		 */
 		if (unlikely(tmpbuf == NULL)) {
 			/* this is the first time we need the compression buffer */
-			tmpbuf = pool_alloc2(pool2_buffer);
-			if (tmpbuf == NULL)
+			if (b_alloc(&tmpbuf) == NULL)
 				goto aborted_xfer; /* no memory */
 		}
 
diff --git a/src/session.c b/src/session.c
index d57a2d5da..05fd72e56 100644
--- a/src/session.c
+++ b/src/session.c
@@ -477,18 +477,15 @@ int session_complete(struct session *s)
 	if (unlikely((s->req = pool_alloc2(pool2_channel)) == NULL))
 		goto out_free_task; /* no memory */
 
-	if (unlikely((s->req->buf = pool_alloc2(pool2_buffer)) == NULL))
+	if (unlikely(b_alloc(&s->req->buf) == NULL))
 		goto out_free_req; /* no memory */
 
 	if (unlikely((s->rep = pool_alloc2(pool2_channel)) == NULL))
 		goto out_free_req_buf; /* no memory */
 
-	if (unlikely((s->rep->buf = pool_alloc2(pool2_buffer)) == NULL))
+	if (unlikely(b_alloc(&s->rep->buf) == NULL))
 		goto out_free_rep; /* no memory */
 
-	/* initialize the request buffer */
-	s->req->buf->size = global.tune.bufsize;
-	b_reset(s->req->buf);
 	channel_init(s->req);
 	s->req->prod = &s->si[0];
 	s->req->cons = &s->si[1];
@@ -504,9 +501,6 @@ int session_complete(struct session *s)
 	s->req->wex = TICK_ETERNITY;
 	s->req->analyse_exp = TICK_ETERNITY;
 
-	/* initialize response buffer */
-	s->rep->buf->size = global.tune.bufsize;
-	b_reset(s->rep->buf);
 	channel_init(s->rep);
 	s->rep->prod = &s->si[1];
 	s->rep->cons = &s->si[0];