diff --git a/src/cache.c b/src/cache.c
index 35568bc55..fdb0f256f 100644
--- a/src/cache.c
+++ b/src/cache.c
@@ -644,7 +644,9 @@ static void http_cache_io_handler(struct appctx *appctx)
 
 	/* Check if the input buffer is avalaible. */
 	if (res->buf.size == 0) {
-		si_cant_put(si);
+		/* buf.size==0 means we failed to get a buffer and were
+		 * already subscribed to a wait list to get a buffer.
+		 */
 		goto out;
 	}
 
diff --git a/src/cli.c b/src/cli.c
index 720a9b451..6329db1ce 100644
--- a/src/cli.c
+++ b/src/cli.c
@@ -550,7 +550,9 @@ static void cli_io_handler(struct appctx *appctx)
 
 	/* Check if the input buffer is avalaible. */
 	if (res->buf.size == 0) {
-		si_cant_put(si);
+		/* buf.size==0 means we failed to get a buffer and were
+		 * already subscribed to a wait list to get a buffer.
+		 */
 		goto out;
 	}
 
diff --git a/src/hlua.c b/src/hlua.c
index ad0f9f92e..f7d271886 100644
--- a/src/hlua.c
+++ b/src/hlua.c
@@ -2942,7 +2942,7 @@ __LJMP static int hlua_channel_append_yield(lua_State *L, int status, lua_KConte
 	 * the request buffer if its not required.
 	 */
 	if (chn->buf.size == 0) {
-		si_cant_put(chn_prod(chn));
+		si_rx_buff_blk(chn_prod(chn));
 		MAY_LJMP(hlua_yieldk(L, 0, 0, hlua_channel_append_yield, TICK_ETERNITY, 0));
 	}
 
@@ -3036,7 +3036,7 @@ __LJMP static int hlua_channel_send_yield(lua_State *L, int status, lua_KContext
 	 * the request buffer if its not required.
 	 */
 	if (chn->buf.size == 0) {
-		si_cant_put(chn_prod(chn));
+		si_rx_buff_blk(chn_prod(chn));
 		MAY_LJMP(hlua_yieldk(L, 0, 0, hlua_channel_send_yield, TICK_ETERNITY, 0));
 	}
 
diff --git a/src/stats.c b/src/stats.c
index 0574260d9..31c4f8540 100644
--- a/src/stats.c
+++ b/src/stats.c
@@ -3049,7 +3049,9 @@ static void http_stats_io_handler(struct appctx *appctx)
 
 	/* Check if the input buffer is avalaible. */
 	if (res->buf.size == 0) {
-		si_cant_put(si);
+		/* already subscribed, we'll be called later once the buffer is
+		 * available.
+		 */
 		goto out;
 	}