diff --git a/src/event/quic/ngx_event_quic.c b/src/event/quic/ngx_event_quic.c
index b0cf056..4687c84 100644
--- a/src/event/quic/ngx_event_quic.c
+++ b/src/event/quic/ngx_event_quic.c
@@ -260,14 +260,7 @@ ngx_quic_new_connection(ngx_connection_t *c, ngx_quic_conf_t *conf,
 
     ngx_queue_init(&qc->free_frames);
 
-    qc->avg_rtt = NGX_QUIC_INITIAL_RTT;
-    qc->rttvar = NGX_QUIC_INITIAL_RTT / 2;
-    qc->min_rtt = NGX_TIMER_INFINITE;
-    qc->first_rtt = NGX_TIMER_INFINITE;
-
-    /*
-     * qc->latest_rtt = 0
-     */
+    ngx_quic_init_rtt(qc);
 
     qc->pto.log = c->log;
     qc->pto.data = c;
diff --git a/src/event/quic/ngx_event_quic_ack.c b/src/event/quic/ngx_event_quic_ack.c
index deeaae1..c7ffd44 100644
--- a/src/event/quic/ngx_event_quic_ack.c
+++ b/src/event/quic/ngx_event_quic_ack.c
@@ -325,6 +325,10 @@ ngx_quic_congestion_ack(ngx_connection_t *c, ngx_quic_frame_t *f)
     qc = ngx_quic_get_connection(c);
     cg = &qc->congestion;
 
+    if (f->pnum < qc->rst_pnum) {
+        return;
+    }
+
     blocked = (cg->in_flight >= cg->window) ? 1 : 0;
 
     cg->in_flight -= f->plen;
@@ -667,6 +671,10 @@ ngx_quic_congestion_lost(ngx_connection_t *c, ngx_quic_frame_t *f)
     qc = ngx_quic_get_connection(c);
     cg = &qc->congestion;
 
+    if (f->pnum < qc->rst_pnum) {
+        return;
+    }
+
     blocked = (cg->in_flight >= cg->window) ? 1 : 0;
 
     cg->in_flight -= f->plen;
diff --git a/src/event/quic/ngx_event_quic_connection.h b/src/event/quic/ngx_event_quic_connection.h
index 4ff0eae..824c92b 100644
--- a/src/event/quic/ngx_event_quic_connection.h
+++ b/src/event/quic/ngx_event_quic_connection.h
@@ -65,6 +65,13 @@ typedef struct ngx_quic_keys_s        ngx_quic_keys_t;
 
 #define ngx_quic_get_socket(c)               ((ngx_quic_socket_t *)((c)->udp))
 
+#define ngx_quic_init_rtt(qc)                                                 \
+    (qc)->avg_rtt = NGX_QUIC_INITIAL_RTT;                                     \
+    (qc)->rttvar = NGX_QUIC_INITIAL_RTT / 2;                                  \
+    (qc)->min_rtt = NGX_TIMER_INFINITE;                                       \
+    (qc)->first_rtt = NGX_TIMER_INFINITE;                                     \
+    (qc)->latest_rtt = 0;
+
 
 typedef enum {
     NGX_QUIC_PATH_IDLE = 0,
@@ -259,6 +266,8 @@ struct ngx_quic_connection_s {
     ngx_quic_streams_t                streams;
     ngx_quic_congestion_t             congestion;
 
+    uint64_t                          rst_pnum;    /* first on validated path */
+
     off_t                             received;
 
     ngx_uint_t                        error;
diff --git a/src/event/quic/ngx_event_quic_migration.c b/src/event/quic/ngx_event_quic_migration.c
index be8e0e3..3c1bbaf 100644
--- a/src/event/quic/ngx_event_quic_migration.c
+++ b/src/event/quic/ngx_event_quic_migration.c
@@ -110,6 +110,7 @@ ngx_quic_handle_path_response_frame(ngx_connection_t *c,
     ngx_uint_t              rst;
     ngx_queue_t            *q;
     ngx_quic_path_t        *path, *prev;
+    ngx_quic_send_ctx_t    *ctx;
     ngx_quic_connection_t  *qc;
 
     qc = ngx_quic_get_connection(c);
@@ -174,6 +175,11 @@ valid:
     }
 
     if (rst) {
+        /* prevent old path packets contribution to congestion control */
+
+        ctx = ngx_quic_get_send_ctx(qc, ssl_encryption_application);
+        qc->rst_pnum = ctx->pnum;
+
         ngx_memzero(&qc->congestion, sizeof(ngx_quic_congestion_t));
 
         qc->congestion.window = ngx_min(10 * qc->tp.max_udp_payload_size,
@@ -181,6 +187,8 @@ valid:
                                            14720));
         qc->congestion.ssthresh = (size_t) -1;
         qc->congestion.recovery_start = ngx_current_msec;
+
+        ngx_quic_init_rtt(qc);
     }
 
     path->validated = 1;