diff --git a/net/slirp.c b/net/slirp.c
index f6dc03963a..1dbd34a9da 100644
--- a/net/slirp.c
+++ b/net/slirp.c
@@ -99,7 +99,7 @@ static void slirp_smb_cleanup(SlirpState *s);
 static inline void slirp_smb_cleanup(SlirpState *s) { }
 #endif
 
-void slirp_output(void *opaque, const uint8_t *pkt, int pkt_len)
+static void net_slirp_output(void *opaque, const uint8_t *pkt, int pkt_len)
 {
     SlirpState *s = opaque;
 
@@ -378,7 +378,8 @@ static int net_slirp_init(NetClientState *peer, const char *model,
                           ipv6, ip6_prefix, vprefix6_len, ip6_host,
                           vhostname, tftp_server_name,
                           tftp_export, bootfile, dhcp,
-                          dns, ip6_dns, dnssearch, vdomainname, s);
+                          dns, ip6_dns, dnssearch, vdomainname,
+                          net_slirp_output, s);
     QTAILQ_INSERT_TAIL(&slirp_stacks, s, entry);
 
     for (config = slirp_configs; config; config = config->next) {
diff --git a/slirp/libslirp.h b/slirp/libslirp.h
index 42e42e9a2a..52dbb9feb5 100644
--- a/slirp/libslirp.h
+++ b/slirp/libslirp.h
@@ -5,6 +5,8 @@
 
 typedef struct Slirp Slirp;
 
+typedef void (*slirp_output)(void *opaque, const uint8_t *pkt, int pkt_len);
+
 int get_dns_addr(struct in_addr *pdns_addr);
 int get_dns6_addr(struct in6_addr *pdns6_addr, uint32_t *scope_id);
 
@@ -17,7 +19,9 @@ Slirp *slirp_init(int restricted, bool in_enabled, struct in_addr vnetwork,
                   const char *tftp_path, const char *bootfile,
                   struct in_addr vdhcp_start, struct in_addr vnameserver,
                   struct in6_addr vnameserver6, const char **vdnssearch,
-                  const char *vdomainname, void *opaque);
+                  const char *vdomainname,
+                  slirp_output output,
+                  void *opaque);
 void slirp_cleanup(Slirp *slirp);
 
 void slirp_pollfds_fill(GArray *pollfds, uint32_t *timeout);
@@ -26,9 +30,6 @@ void slirp_pollfds_poll(GArray *pollfds, int select_error);
 
 void slirp_input(Slirp *slirp, const uint8_t *pkt, int pkt_len);
 
-/* you must provide the following functions: */
-void slirp_output(void *opaque, const uint8_t *pkt, int pkt_len);
-
 int slirp_add_hostfwd(Slirp *slirp, int is_udp,
                       struct in_addr host_addr, int host_port,
                       struct in_addr guest_addr, int guest_port);
diff --git a/slirp/ncsi.c b/slirp/ncsi.c
index 7116034afc..d7701f7785 100644
--- a/slirp/ncsi.c
+++ b/slirp/ncsi.c
@@ -163,5 +163,5 @@ void ncsi_input(Slirp *slirp, const uint8_t *pkt, int pkt_len)
     *pchecksum = htonl(checksum);
     ncsi_rsp_len += 4;
 
-    slirp_output(slirp->opaque, ncsi_reply, ETH_HLEN + ncsi_rsp_len);
+    slirp->output(slirp->opaque, ncsi_reply, ETH_HLEN + ncsi_rsp_len);
 }
diff --git a/slirp/slirp.c b/slirp/slirp.c
index 322edf51eb..b0380c5eaa 100644
--- a/slirp/slirp.c
+++ b/slirp/slirp.c
@@ -287,12 +287,15 @@ Slirp *slirp_init(int restricted, bool in_enabled, struct in_addr vnetwork,
                   const char *tftp_path, const char *bootfile,
                   struct in_addr vdhcp_start, struct in_addr vnameserver,
                   struct in6_addr vnameserver6, const char **vdnssearch,
-                  const char *vdomainname, void *opaque)
+                  const char *vdomainname,
+                  slirp_output output,
+                  void *opaque)
 {
     Slirp *slirp = g_malloc0(sizeof(Slirp));
 
     slirp_init_once();
 
+    slirp->output = output;
     slirp->grand = g_rand_new();
     slirp->restricted = restricted;
 
@@ -832,7 +835,7 @@ static void arp_input(Slirp *slirp, const uint8_t *pkt, int pkt_len)
             rah->ar_sip = ah->ar_tip;
             memcpy(rah->ar_tha, ah->ar_sha, ETH_ALEN);
             rah->ar_tip = ah->ar_sip;
-            slirp_output(slirp->opaque, arp_reply, sizeof(arp_reply));
+            slirp->output(slirp->opaque, arp_reply, sizeof(arp_reply));
         }
         break;
     case ARPOP_REPLY:
@@ -932,7 +935,7 @@ static int if_encap4(Slirp *slirp, struct mbuf *ifm, struct ethhdr *eh,
             /* target IP */
             rah->ar_tip = iph->ip_dst.s_addr;
             slirp->client_ipaddr = iph->ip_dst;
-            slirp_output(slirp->opaque, arp_req, sizeof(arp_req));
+            slirp->output(slirp->opaque, arp_req, sizeof(arp_req));
             ifm->resolution_requested = true;
 
             /* Expire request and drop outgoing packet after 1 second */
@@ -1018,7 +1021,7 @@ int if_encap(Slirp *slirp, struct mbuf *ifm)
                 eh->h_dest[0], eh->h_dest[1], eh->h_dest[2],
                 eh->h_dest[3], eh->h_dest[4], eh->h_dest[5]));
     memcpy(buf + sizeof(struct ethhdr), ifm->m_data, ifm->m_len);
-    slirp_output(slirp->opaque, buf, ifm->m_len + ETH_HLEN);
+    slirp->output(slirp->opaque, buf, ifm->m_len + ETH_HLEN);
     return 1;
 }
 
diff --git a/slirp/slirp.h b/slirp/slirp.h
index b80725a0d6..e3d65d68ec 100644
--- a/slirp/slirp.h
+++ b/slirp/slirp.h
@@ -220,6 +220,7 @@ struct Slirp {
     GRand *grand;
     QEMUTimer *ra_timer;
 
+    slirp_output output;
     void *opaque;
 };
 
