diff --git a/bindings/java/src/jni/generate.pl b/bindings/java/src/jni/generate.pl
index ea50fd1f..7538173f 100644
--- a/bindings/java/src/jni/generate.pl
+++ b/bindings/java/src/jni/generate.pl
@@ -659,7 +659,7 @@ my %classes = (
          plat => '*'
       },
       {
-         name => 'hwaddr', type => 'String',
+         name => 'hwaddr', type => 'NetAddress',
          desc => '',
          plat => '*'
       },
diff --git a/include/sigar.h b/include/sigar.h
index 5de91ccd..41c1295f 100644
--- a/include/sigar.h
+++ b/include/sigar.h
@@ -395,11 +395,13 @@ typedef struct {
     enum {
         SIGAR_AF_UNSPEC,
         SIGAR_AF_INET,
-        SIGAR_AF_INET6
+        SIGAR_AF_INET6,
+        SIGAR_AF_LINK
     } family;
     union {
         sigar_uint32_t in;
         sigar_uint32_t in6[4];
+        unsigned char mac[8];
     } addr;
 } sigar_net_address_t;
 
@@ -478,9 +480,9 @@ SIGAR_DECLARE(int) sigar_net_route_list_destroy(sigar_t *sigar,
 
 typedef struct {
     char name[16];
-    char hwaddr[64];
     char type[64];
     char description[256];
+    sigar_net_address_t hwaddr;
     sigar_net_address_t address;
     sigar_net_address_t destination;
     sigar_net_address_t broadcast;
diff --git a/include/sigar_private.h b/include/sigar_private.h
index a90417ef..df68e993 100644
--- a/include/sigar_private.h
+++ b/include/sigar_private.h
@@ -196,10 +196,15 @@ int sigar_net_connection_list_grow(sigar_net_connection_list_t *connlist);
     (a).addr.in = val; \
     (a).family = SIGAR_AF_INET
 
-#define sigar_net_address6_set(addr, val) \
+#define sigar_net_address6_set(a, val) \
     memcpy(&((a).addr.in6), val, sizeof((a).addr.in6)); \
     (a).family = SIGAR_AF_INET6
 
+#define sigar_net_address_mac_set(a, val, len) \
+    if (len == 0) SIGAR_ZERO(&((a).addr.mac); \
+    else memcpy(&((a).addr.mac), val, len); \
+    (a).family = SIGAR_AF_LINK
+
 int sigar_who_list_create(sigar_who_list_t *wholist);
 
 int sigar_who_list_grow(sigar_who_list_t *wholist);
@@ -209,7 +214,7 @@ int sigar_who_list_grow(sigar_who_list_t *wholist);
         sigar_who_list_grow(wholist); \
     }
 
-void sigar_hwaddr_format(char *buff, unsigned char *ptr);
+int sigar_hwaddr_format(char *buff, unsigned char *ptr);
 
 #define sigar_hwaddr_set_null(ifconfig) \
     memcpy(ifconfig->hwaddr, SIGAR_NULL_HWADDR, sizeof(SIGAR_NULL_HWADDR))
diff --git a/src/os/darwin/darwin_sigar.c b/src/os/darwin/darwin_sigar.c
index 1dcd0d57..8daeaaae 100644
--- a/src/os/darwin/darwin_sigar.c
+++ b/src/os/darwin/darwin_sigar.c
@@ -1617,8 +1617,10 @@ int sigar_net_interface_config_get(sigar_t *sigar, const char *name,
     SIGAR_SSTRCPY(ifconfig->name, name);
 
     sdl = (struct sockaddr_dl *)(ifm + 1);
-    sigar_hwaddr_format(ifconfig->hwaddr,
-                        (unsigned char *)LLADDR(sdl));
+
+    sigar_net_address_mac_set(ifconfig->hwaddr,
+                              LLADDR(sdl),
+                              sdl->sdl_alen);
 
     ifconfig->flags = ifm->ifm_flags;
     ifconfig->mtu = ifm->ifm_data.ifi_mtu;
diff --git a/src/sigar.c b/src/sigar.c
index 7fe6bb7c..484534eb 100644
--- a/src/sigar.c
+++ b/src/sigar.c
@@ -1210,11 +1210,12 @@ int sigar_resource_limit_get(sigar_t *sigar,
 }
 #endif
 
-void sigar_hwaddr_format(char *buff, unsigned char *ptr)
+int sigar_hwaddr_format(char *buff, unsigned char *ptr)
 {
     sprintf(buff, "%02X:%02X:%02X:%02X:%02X:%02X",
             (ptr[0] & 0377), (ptr[1] & 0377), (ptr[2] & 0377),
             (ptr[3] & 0377), (ptr[4] & 0377), (ptr[5] & 0377));
+    return SIGAR_OK;
 }
 
 #if !defined(WIN32) && !defined(DARWIN) && !defined(__FreeBSD__) && !defined(NETWARE)
@@ -1657,6 +1658,8 @@ SIGAR_DECLARE(int) sigar_net_address_to_string(sigar_t *sigar,
         return sigar_inet_ntoa(sigar, address->addr.in, addr_str);
       case SIGAR_AF_UNSPEC:
         return sigar_inet_ntoa(sigar, 0, addr_str); /*XXX*/
+      case SIGAR_AF_LINK:
+        return sigar_hwaddr_format(addr_str, &address->addr.mac[0]);
       default:
         return EINVAL;
     }