diff --git a/lib/asyn-ares.c b/lib/asyn-ares.c
index 4ea2e0724c..007f1d7123 100644
--- a/lib/asyn-ares.c
+++ b/lib/asyn-ares.c
@@ -48,6 +48,7 @@
 #endif
 
 #include "urldata.h"
+#include "cfilters.h"
 #include "sendf.h"
 #include "hostip.h"
 #include "hash.h"
@@ -757,7 +758,8 @@ struct Curl_addrinfo *Curl_async_getaddrinfo(struct Curl_easy *data,
                  (pf == PF_UNSPEC) ? "A+AAAA" :
                  ((pf == PF_INET) ? "A" : "AAAA"));
     hints.ai_family = pf;
-    hints.ai_socktype = (data->conn->transport == TRNSPRT_TCP) ?
+    hints.ai_socktype =
+      (Curl_conn_get_transport(data, data->conn) == TRNSPRT_TCP) ?
       SOCK_STREAM : SOCK_DGRAM;
     /* Since the service is a numerical one, set the hint flags
      * accordingly to save a call to getservbyname in inside C-Ares
diff --git a/lib/asyn-thrdd.c b/lib/asyn-thrdd.c
index 454e31b8b8..1ede868820 100644
--- a/lib/asyn-thrdd.c
+++ b/lib/asyn-thrdd.c
@@ -55,6 +55,7 @@
 #endif
 
 #include "urldata.h"
+#include "cfilters.h"
 #include "sendf.h"
 #include "hostip.h"
 #include "hash.h"
@@ -741,7 +742,8 @@ struct Curl_addrinfo *Curl_async_getaddrinfo(struct Curl_easy *data,
 
   memset(&hints, 0, sizeof(hints));
   hints.ai_family = pf;
-  hints.ai_socktype = (data->conn->transport == TRNSPRT_TCP) ?
+  hints.ai_socktype =
+    (Curl_conn_get_transport(data, data->conn) == TRNSPRT_TCP) ?
     SOCK_STREAM : SOCK_DGRAM;
 
   /* fire up a new resolver thread! */
diff --git a/lib/cf-https-connect.c b/lib/cf-https-connect.c
index 474769d1cb..b89ed80e55 100644
--- a/lib/cf-https-connect.c
+++ b/lib/cf-https-connect.c
@@ -55,6 +55,7 @@ struct cf_hc_baller {
   CURLcode result;
   struct curltime started;
   int reply_ms;
+  unsigned char transport;
   enum alpnid alpn_id;
   BIT(shutdown);
 };
@@ -122,12 +123,15 @@ struct cf_hc_ctx {
 };
 
 static void cf_hc_baller_assign(struct cf_hc_baller *b,
-                                enum alpnid alpn_id)
+                                enum alpnid alpn_id,
+                                unsigned char def_transport)
 {
   b->alpn_id = alpn_id;
+  b->transport = def_transport;
   switch(b->alpn_id) {
   case ALPN_h3:
     b->name = "h3";
+    b->transport = TRNSPRT_QUIC;
     break;
   case ALPN_h2:
     b->name = "h2";
@@ -218,6 +222,7 @@ static CURLcode baller_connected(struct Curl_cfilter *cf,
                 winner->name, (int)curlx_timediff(curlx_now(),
                                                   winner->started));
 
+  /* install the winning filter below this one. */
   cf->next = winner->cf;
   winner->cf = NULL;
 
@@ -312,7 +317,7 @@ static CURLcode cf_hc_connect(struct Curl_cfilter *cf,
       DEBUGASSERT(!ctx->ballers[i].cf);
     CURL_TRC_CF(data, cf, "connect, init");
     ctx->started = now;
-    cf_hc_baller_init(&ctx->ballers[0], cf, data, cf->conn->transport);
+    cf_hc_baller_init(&ctx->ballers[0], cf, data, ctx->ballers[0].transport);
     if(ctx->baller_count > 1) {
       Curl_expire(data, ctx->soft_eyeballs_timeout_ms, EXPIRE_ALPN_EYEBALLS);
       CURL_TRC_CF(data, cf, "set next attempt to start in %" FMT_TIMEDIFF_T
@@ -331,7 +336,7 @@ static CURLcode cf_hc_connect(struct Curl_cfilter *cf,
     }
 
     if(time_to_start_next(cf, data, 1, now)) {
-      cf_hc_baller_init(&ctx->ballers[1], cf, data, cf->conn->transport);
+      cf_hc_baller_init(&ctx->ballers[1], cf, data, ctx->ballers[1].transport);
     }
 
     if((ctx->baller_count > 1) && cf_hc_baller_is_active(&ctx->ballers[1])) {
@@ -574,7 +579,8 @@ struct Curl_cftype Curl_cft_http_connect = {
 
 static CURLcode cf_hc_create(struct Curl_cfilter **pcf,
                              struct Curl_easy *data,
-                             enum alpnid *alpnids, size_t alpn_count)
+                             enum alpnid *alpnids, size_t alpn_count,
+                             unsigned char def_transport)
 {
   struct Curl_cfilter *cf = NULL;
   struct cf_hc_ctx *ctx;
@@ -596,7 +602,7 @@ static CURLcode cf_hc_create(struct Curl_cfilter **pcf,
     goto out;
   }
   for(i = 0; i < alpn_count; ++i)
-    cf_hc_baller_assign(&ctx->ballers[i], alpnids[i]);
+    cf_hc_baller_assign(&ctx->ballers[i], alpnids[i], def_transport);
   for(; i < CURL_ARRAYSIZE(ctx->ballers); ++i)
     ctx->ballers[i].alpn_id = ALPN_none;
   ctx->baller_count = alpn_count;
@@ -616,13 +622,14 @@ out:
 static CURLcode cf_http_connect_add(struct Curl_easy *data,
                                     struct connectdata *conn,
                                     int sockindex,
-                                    enum alpnid *alpn_ids, size_t alpn_count)
+                                    enum alpnid *alpn_ids, size_t alpn_count,
+                                    unsigned char def_transport)
 {
   struct Curl_cfilter *cf;
   CURLcode result = CURLE_OK;
 
   DEBUGASSERT(data);
-  result = cf_hc_create(&cf, data, alpn_ids, alpn_count);
+  result = cf_hc_create(&cf, data, alpn_ids, alpn_count, def_transport);
   if(result)
     goto out;
   Curl_conn_cf_add(data, conn, sockindex, cf);
@@ -679,7 +686,7 @@ CURLcode Curl_cf_https_setup(struct Curl_easy *data,
           continue;
         switch(alpn) {
         case ALPN_h3:
-          if(Curl_conn_may_http3(data, conn))
+          if(Curl_conn_may_http3(data, conn, conn->transport_wanted))
             break;  /* not possible */
           if(data->state.http_neg.allowed & CURL_HTTP_V3x) {
             CURL_TRC_CF(data, cf, "adding h3 via HTTPS-RR");
@@ -708,7 +715,7 @@ CURLcode Curl_cf_https_setup(struct Curl_easy *data,
     if((alpn_count < CURL_ARRAYSIZE(alpn_ids)) &&
        (data->state.http_neg.wanted & CURL_HTTP_V3x) &&
        !cf_https_alpns_contain(ALPN_h3, alpn_ids, alpn_count)) {
-      result = Curl_conn_may_http3(data, conn);
+      result = Curl_conn_may_http3(data, conn, conn->transport_wanted);
       if(!result) {
         CURL_TRC_CF(data, cf, "adding wanted h3");
         alpn_ids[alpn_count++] = ALPN_h3;
@@ -733,7 +740,9 @@ CURLcode Curl_cf_https_setup(struct Curl_easy *data,
   /* If we identified ALPNs to use, install our filter. Otherwise,
    * install nothing, so our call will use a default connect setup. */
   if(alpn_count) {
-    result = cf_http_connect_add(data, conn, sockindex, alpn_ids, alpn_count);
+    result = cf_http_connect_add(data, conn, sockindex,
+                                 alpn_ids, alpn_count,
+                                 conn->transport_wanted);
   }
 
 out:
diff --git a/lib/cf-socket.c b/lib/cf-socket.c
index 2a7311eb3b..273258feaf 100644
--- a/lib/cf-socket.c
+++ b/lib/cf-socket.c
@@ -1683,6 +1683,10 @@ static CURLcode cf_socket_query(struct Curl_cfilter *cf,
     DEBUGASSERT(pres2);
     *((curl_socket_t *)pres2) = ctx->sock;
     return CURLE_OK;
+  case CF_QUERY_TRANSPORT:
+    DEBUGASSERT(pres1);
+    *pres1 = ctx->transport;
+    return CURLE_OK;
   case CF_QUERY_REMOTE_ADDR:
     DEBUGASSERT(pres2);
     *((const struct Curl_sockaddr_ex **)pres2) = cf->connected ?
@@ -2193,7 +2197,7 @@ CURLcode Curl_conn_tcp_listen_set(struct Curl_easy *data,
     result = CURLE_OUT_OF_MEMORY;
     goto out;
   }
-  ctx->transport = conn->transport;
+  ctx->transport = TRNSPRT_TCP;
   ctx->sock = *s;
   ctx->listening = TRUE;
   ctx->accepted = FALSE;
diff --git a/lib/cfilters.c b/lib/cfilters.c
index e3247f72c9..01f1e28218 100644
--- a/lib/cfilters.c
+++ b/lib/cfilters.c
@@ -606,6 +606,13 @@ bool Curl_conn_is_multiplex(struct connectdata *conn, int sockindex)
   return FALSE;
 }
 
+unsigned char Curl_conn_get_transport(struct Curl_easy *data,
+                                      struct connectdata *conn)
+{
+  struct Curl_cfilter *cf = conn->cfilter[FIRSTSOCKET];
+  return Curl_conn_cf_get_transport(cf, data);
+}
+
 unsigned char Curl_conn_http_version(struct Curl_easy *data,
                                      struct connectdata *conn)
 {
@@ -794,6 +801,15 @@ curl_socket_t Curl_conn_cf_get_socket(struct Curl_cfilter *cf,
   return CURL_SOCKET_BAD;
 }
 
+unsigned char Curl_conn_cf_get_transport(struct Curl_cfilter *cf,
+                                         struct Curl_easy *data)
+{
+  int transport = 0;
+  if(cf && !cf->cft->query(cf, data, CF_QUERY_TRANSPORT, &transport, NULL))
+    return (unsigned char)transport;
+  return (unsigned char)(data->conn ? data->conn->transport_wanted : 0);
+}
+
 static const struct Curl_sockaddr_ex *
 cf_get_remote_addr(struct Curl_cfilter *cf, struct Curl_easy *data)
 {
diff --git a/lib/cfilters.h b/lib/cfilters.h
index b28ca998e0..39d906d673 100644
--- a/lib/cfilters.h
+++ b/lib/cfilters.h
@@ -175,6 +175,7 @@ typedef CURLcode Curl_cft_cntrl(struct Curl_cfilter *cf,
 #define CF_QUERY_HOST_PORT         11  /* port       const char * */
 #define CF_QUERY_SSL_INFO          12  /* -    struct curl_tlssessioninfo * */
 #define CF_QUERY_SSL_CTX_INFO      13  /* -    struct curl_tlssessioninfo * */
+#define CF_QUERY_TRANSPORT         14  /* TRNSPRT_*  - * */
 
 /**
  * Query the cfilter for properties. Filters ignorant of a query will
@@ -350,6 +351,9 @@ CURLcode Curl_conn_cf_get_ip_info(struct Curl_cfilter *cf,
 bool Curl_conn_cf_needs_flush(struct Curl_cfilter *cf,
                               struct Curl_easy *data);
 
+unsigned char Curl_conn_cf_get_transport(struct Curl_cfilter *cf,
+                                         struct Curl_easy *data);
+
 #define CURL_CF_SSL_DEFAULT  -1
 #define CURL_CF_SSL_DISABLE  0
 #define CURL_CF_SSL_ENABLE   1
@@ -410,6 +414,10 @@ bool Curl_conn_is_multiplex(struct connectdata *conn, int sockindex);
 unsigned char Curl_conn_http_version(struct Curl_easy *data,
                                      struct connectdata *conn);
 
+/* Get the TRNSPRT_* the connection is using */
+unsigned char Curl_conn_get_transport(struct Curl_easy *data,
+                                      struct connectdata *conn);
+
 /**
  * Close the filter chain at `sockindex` for connection `data->conn`.
   * Filters remain in place and may be connected again afterwards.
diff --git a/lib/connect.c b/lib/connect.c
index c894fe62b0..5d9486394a 100644
--- a/lib/connect.c
+++ b/lib/connect.c
@@ -1515,7 +1515,8 @@ CURLcode Curl_conn_setup(struct Curl_easy *data,
 
   /* Still no cfilter set, apply default. */
   if(!conn->cfilter[sockindex]) {
-    result = cf_setup_add(data, conn, sockindex, conn->transport, ssl_mode);
+    result = cf_setup_add(data, conn, sockindex,
+                          conn->transport_wanted, ssl_mode);
     if(result)
       goto out;
   }
diff --git a/lib/ftp.c b/lib/ftp.c
index 5e505887b1..06c486bc91 100644
--- a/lib/ftp.c
+++ b/lib/ftp.c
@@ -1065,7 +1065,8 @@ static CURLcode ftp_state_use_port(struct Curl_easy *data,
   /* step 2, create a socket for the requested address */
   error = 0;
   for(ai = res; ai; ai = ai->ai_next) {
-    if(Curl_socket_open(data, ai, NULL, conn->transport, &portsock)) {
+    if(Curl_socket_open(data, ai, NULL,
+                        Curl_conn_get_transport(data, conn), &portsock)) {
       error = SOCKERRNO;
       continue;
     }
diff --git a/lib/hostip6.c b/lib/hostip6.c
index 35cc2d737b..ce7f5050ea 100644
--- a/lib/hostip6.c
+++ b/lib/hostip6.c
@@ -44,6 +44,7 @@
 #endif
 
 #include "urldata.h"
+#include "cfilters.h"
 #include "sendf.h"
 #include "hostip.h"
 #include "hash.h"
@@ -104,7 +105,8 @@ struct Curl_addrinfo *Curl_sync_getaddrinfo(struct Curl_easy *data,
 
   memset(&hints, 0, sizeof(hints));
   hints.ai_family = pf;
-  hints.ai_socktype = (data->conn->transport == TRNSPRT_TCP) ?
+  hints.ai_socktype =
+    (Curl_conn_get_transport(data, data->conn) == TRNSPRT_TCP) ?
     SOCK_STREAM : SOCK_DGRAM;
 
 #ifndef USE_RESOLVE_ON_IPS
diff --git a/lib/http.c b/lib/http.c
index 32e54c2683..e5a0696274 100644
--- a/lib/http.c
+++ b/lib/http.c
@@ -232,7 +232,7 @@ CURLcode Curl_http_setup_conn(struct Curl_easy *data,
   connkeep(conn, "HTTP default");
   if(data->state.http_neg.wanted == CURL_HTTP_V3x) {
     /* only HTTP/3, needs to work */
-    CURLcode result = Curl_conn_may_http3(data, conn);
+    CURLcode result = Curl_conn_may_http3(data, conn, conn->transport_wanted);
     if(result)
       return result;
   }
diff --git a/lib/tftp.c b/lib/tftp.c
index 5ed7258d38..5ea986dbb4 100644
--- a/lib/tftp.c
+++ b/lib/tftp.c
@@ -1369,7 +1369,7 @@ static CURLcode tftp_setup_connection(struct Curl_easy *data,
 {
   char *type;
 
-  conn->transport = TRNSPRT_UDP;
+  conn->transport_wanted = TRNSPRT_UDP;
 
   /* TFTP URLs support an extension like ";mode=<typecode>" that
    * we will try to get now! */
diff --git a/lib/url.c b/lib/url.c
index 1f73c1e3ac..e4f250f54a 100644
--- a/lib/url.c
+++ b/lib/url.c
@@ -1464,7 +1464,7 @@ static struct connectdata *allocate_conn(struct Curl_easy *data)
 #endif
   conn->ip_version = data->set.ipver;
   conn->connect_only = data->set.connect_only;
-  conn->transport = TRNSPRT_TCP; /* most of them are TCP streams */
+  conn->transport_wanted = TRNSPRT_TCP; /* most of them are TCP streams */
 
   /* Initialize the attached xfers bitset */
   Curl_uint_spbset_init(&conn->xfers_attached);
@@ -3235,7 +3235,7 @@ static CURLcode parse_connect_to_slist(struct Curl_easy *data,
           neg->wanted = neg->allowed = CURL_HTTP_V2x;
           break;
         case ALPN_h3:
-          conn->transport = TRNSPRT_QUIC;
+          conn->transport_wanted = TRNSPRT_QUIC;
           neg->wanted = neg->allowed = CURL_HTTP_V3x;
           break;
         default: /* should not be possible */
@@ -3312,7 +3312,7 @@ static CURLcode resolve_server(struct Curl_easy *data,
 
     if(unix_path) {
       /* This only works if previous transport is TRNSPRT_TCP. Check it? */
-      conn->transport = TRNSPRT_UNIX;
+      conn->transport_wanted = TRNSPRT_UNIX;
       return resolve_unix(data, conn, unix_path, pdns);
     }
   }
diff --git a/lib/urldata.h b/lib/urldata.h
index 63bee65dc9..e54721dd98 100644
--- a/lib/urldata.h
+++ b/lib/urldata.h
@@ -785,7 +785,10 @@ struct connectdata {
 #ifndef CURL_DISABLE_PROXY
   unsigned char proxy_alpn; /* APLN of proxy tunnel, CURL_HTTP_VERSION* */
 #endif
-  unsigned char transport; /* one of the TRNSPRT_* defines */
+  unsigned char transport_wanted; /* one of the TRNSPRT_* defines. Not
+   necessarily the transport the connection ends using due to Alt-Svc
+   and happy eyeballing. Use `Curl_conn_get_transport() for actual value
+   once the connection is set up. */
   unsigned char ip_version; /* copied from the Curl_easy at creation time */
   /* HTTP version last responded with by the server.
    * 0 at start, then one of 09, 10, 11, etc. */
diff --git a/lib/vquic/vquic.c b/lib/vquic/vquic.c
index 1eb67f516f..691c0d3fa7 100644
--- a/lib/vquic/vquic.c
+++ b/lib/vquic/vquic.c
@@ -703,9 +703,10 @@ CURLcode Curl_cf_quic_create(struct Curl_cfilter **pcf,
 }
 
 CURLcode Curl_conn_may_http3(struct Curl_easy *data,
-                             const struct connectdata *conn)
+                             const struct connectdata *conn,
+                             unsigned char transport)
 {
-  if(conn->transport == TRNSPRT_UNIX) {
+  if(transport == TRNSPRT_UNIX) {
     /* cannot do QUIC over a Unix domain socket */
     return CURLE_QUIC_CONNECT_ERROR;
   }
@@ -730,10 +731,12 @@ CURLcode Curl_conn_may_http3(struct Curl_easy *data,
 #else /* USE_HTTP3 */
 
 CURLcode Curl_conn_may_http3(struct Curl_easy *data,
-                             const struct connectdata *conn)
+                             const struct connectdata *conn,
+                             unsigned char transport)
 {
   (void)conn;
   (void)data;
+  (void)transport;
   DEBUGF(infof(data, "QUIC is not supported in this build"));
   return CURLE_NOT_BUILT_IN;
 }
diff --git a/lib/vquic/vquic.h b/lib/vquic/vquic.h
index dbf63b1f6f..3577a857e3 100644
--- a/lib/vquic/vquic.h
+++ b/lib/vquic/vquic.h
@@ -54,6 +54,7 @@ extern struct Curl_cftype Curl_cft_http3;
 #endif /* !USE_HTTP3 */
 
 CURLcode Curl_conn_may_http3(struct Curl_easy *data,
-                             const struct connectdata *conn);
+                             const struct connectdata *conn,
+                             unsigned char transport);
 
 #endif /* HEADER_CURL_VQUIC_QUIC_H */
diff --git a/lib/vtls/wolfssl.c b/lib/vtls/wolfssl.c
index 8005fa3f59..c3560e8b8d 100644
--- a/lib/vtls/wolfssl.c
+++ b/lib/vtls/wolfssl.c
@@ -964,6 +964,7 @@ CURLcode Curl_wssl_ctx_init(struct wssl_ctx *wctx,
   size_t idx = 0;
 #endif
   CURLcode result = CURLE_FAILED_INIT;
+  unsigned char transport;
 
   DEBUGASSERT(!wctx->ssl_ctx);
   DEBUGASSERT(!wctx->ssl);
@@ -973,6 +974,8 @@ CURLcode Curl_wssl_ctx_init(struct wssl_ctx *wctx,
     goto out;
   }
   Curl_alpn_copy(&alpns, alpns_requested);
+  DEBUGASSERT(cf->next);
+  transport = Curl_conn_cf_get_transport(cf->next, data);
 
 #if LIBWOLFSSL_VERSION_HEX < 0x04002000 /* 4.2.0 (2019) */
   req_method = wolfSSLv23_client_method();
@@ -1103,7 +1106,7 @@ CURLcode Curl_wssl_ctx_init(struct wssl_ctx *wctx,
 #endif
 
   curves = conn_config->curves;
-  if(!curves && cf->conn->transport == TRNSPRT_QUIC)
+  if(!curves && (transport == TRNSPRT_QUIC))
     curves = (char *)CURL_UNCONST(QUIC_GROUPS);
 
   if(curves) {
@@ -1244,8 +1247,7 @@ CURLcode Curl_wssl_ctx_init(struct wssl_ctx *wctx,
   }
 #endif
 
-  if(ssl_config->primary.cache_session &&
-     cf->conn->transport != TRNSPRT_QUIC) {
+  if(ssl_config->primary.cache_session && (transport != TRNSPRT_QUIC)) {
     /* Register to get notified when a new session is received */
     wolfSSL_CTX_sess_set_new_cb(wctx->ssl_ctx, wssl_vtls_new_session_cb);
   }
@@ -1291,7 +1293,7 @@ CURLcode Curl_wssl_ctx_init(struct wssl_ctx *wctx,
 
   wolfSSL_set_app_data(wctx->ssl, ssl_user_data);
 #ifdef WOLFSSL_QUIC
-  if(cf->conn->transport == TRNSPRT_QUIC)
+  if(transport == TRNSPRT_QUIC)
     wolfSSL_set_quic_use_legacy_codepoint(wctx->ssl, 0);
 #endif