diff --git a/src/http_act.c b/src/http_act.c
index 5d3d2e2..67eca31 100644
--- a/src/http_act.c
+++ b/src/http_act.c
@@ -1125,6 +1125,7 @@
 
 		data = htx->data - co_data(res);
 		c_adv(res, data);
+		htx->first = -1;
 		res->total += data;
 	}
 
diff --git a/src/http_ana.c b/src/http_ana.c
index a276527..eac5944 100644
--- a/src/http_ana.c
+++ b/src/http_ana.c
@@ -2669,6 +2669,7 @@
 	htx->flags |= HTX_FL_PROXY_RESP;
 	data = htx->data - co_data(res);
 	c_adv(res, data);
+	htx->first = -1;
 	res->total += data;
 
 	channel_auto_read(req);
@@ -4258,6 +4259,7 @@
 	 */
 	data = htx->data - co_data(res);
 	c_adv(res, data);
+	htx->first = -1;
 	res->total += data;
 
 	/* return without error. */
@@ -4564,6 +4566,7 @@
 			htx->flags |= HTX_FL_PROXY_RESP;
 			data = htx->data - co_data(chn);
 			c_adv(chn, data);
+			htx->first = -1;
 			chn->total += data;
 		}
 	}
@@ -4596,6 +4599,7 @@
 			htx->flags |= HTX_FL_PROXY_RESP;
 			data = htx->data - co_data(chn);
 			c_adv(chn, data);
+			htx->first = -1;
 			chn->total += data;
 		}
 	}
@@ -4719,6 +4723,7 @@
 
 	data = htx->data - co_data(res);
 	c_adv(res, data);
+	htx->first = -1;
 	res->total += data;
 	return 0;
 
@@ -4795,6 +4800,7 @@
 	htx->flags |= HTX_FL_PROXY_RESP;
 	data = htx->data - co_data(res);
 	c_adv(res, data);
+	htx->first = -1;
 	res->total += data;
 
 	channel_auto_read(&s->req);