diff --git a/net/tap-aix.c b/net/tap-aix.c
index 3f9ccddda7ca8395d7528a13e1a392840c6776e4..27143ff36b0bbe00b3d249a9885be6d90533e317 100644
--- a/net/tap-aix.c
+++ b/net/tap-aix.c
@@ -36,3 +36,7 @@ int tap_set_sndbuf(int fd, QemuOpts *opts)
     return 0;
 }
 
+int tap_probe_vnet_hdr(int fd)
+{
+    return 0;
+}
diff --git a/net/tap-bsd.c b/net/tap-bsd.c
index e28615fba9679476ea3b634742ea66e0f520fde8..1cdde90009fce278a42b90a7ed51f5a6cf8588b4 100644
--- a/net/tap-bsd.c
+++ b/net/tap-bsd.c
@@ -65,3 +65,8 @@ int tap_set_sndbuf(int fd, QemuOpts *opts)
 {
     return 0;
 }
+
+int tap_probe_vnet_hdr(int fd)
+{
+    return 0;
+}
diff --git a/net/tap-linux.c b/net/tap-linux.c
index 6c3b6e311b4f2fb4a890cde5acd9e2823fe75876..0059404069f9ece747e2e8da90f053ce348cb2e3 100644
--- a/net/tap-linux.c
+++ b/net/tap-linux.c
@@ -99,3 +99,15 @@ int tap_set_sndbuf(int fd, QemuOpts *opts)
     }
     return 0;
 }
+
+int tap_probe_vnet_hdr(int fd)
+{
+    struct ifreq ifr;
+
+    if (ioctl(fd, TUNGETIFF, &ifr) != 0) {
+        qemu_error("TUNGETIFF ioctl() failed: %s\n", strerror(errno));
+        return 0;
+    }
+
+    return ifr.ifr_flags & IFF_VNET_HDR;
+}
diff --git a/net/tap-solaris.c b/net/tap-solaris.c
index de5855aa06d2ae3f4b6fe877cb6513b945657f7c..3f48e573289e9cabc024f65169ef8d5556e0ec9e 100644
--- a/net/tap-solaris.c
+++ b/net/tap-solaris.c
@@ -188,3 +188,8 @@ int tap_set_sndbuf(int fd, QemuOpts *opts)
 {
     return 0;
 }
+
+int tap_probe_vnet_hdr(int fd)
+{
+    return 0;
+}
diff --git a/net/tap.c b/net/tap.c
index df2cfbe13c308b2375e8651b816460df31aba3f5..3f6722ea6cf1cffe9d5298cb9b40f6ebb956cb0b 100644
--- a/net/tap.c
+++ b/net/tap.c
@@ -239,18 +239,6 @@ void tap_using_vnet_hdr(VLANClientState *vc, int using_vnet_hdr)
     s->using_vnet_hdr = using_vnet_hdr;
 }
 
-static int tap_probe_vnet_hdr(int fd)
-{
-    struct ifreq ifr;
-
-    if (ioctl(fd, TUNGETIFF, &ifr) != 0) {
-        qemu_error("TUNGETIFF ioctl() failed: %s\n", strerror(errno));
-        return 0;
-    }
-
-    return ifr.ifr_flags & IFF_VNET_HDR;
-}
-
 void tap_set_offload(VLANClientState *vc, int csum, int tso4,
                      int tso6, int ecn, int ufo)
 {
diff --git a/net/tap.h b/net/tap.h
index 0d67c249cffbc36f934d86cb676e5dfb56156554..de729a79dbc5640c6cdc73a743af0fef1ad27a12 100644
--- a/net/tap.h
+++ b/net/tap.h
@@ -44,5 +44,6 @@ void tap_using_vnet_hdr(VLANClientState *vc, int using_vnet_hdr);
 void tap_set_offload(VLANClientState *vc, int csum, int tso4, int tso6, int ecn, int ufo);
 
 int tap_set_sndbuf(int fd, QemuOpts *opts);
+int tap_probe_vnet_hdr(int fd);
 
 #endif /* QEMU_NET_TAP_H */