diff --git a/include/sigar.h b/include/sigar.h
index 065e3482..989e121c 100644
--- a/include/sigar.h
+++ b/include/sigar.h
@@ -467,7 +467,8 @@ typedef struct {
         netmask,
         flags,
         mtu,
-        metric;
+        metric,
+        speed;
 } sigar_net_interface_config_t;
 
 SIGAR_DECLARE(int)
diff --git a/src/os/darwin/darwin_sigar.c b/src/os/darwin/darwin_sigar.c
index 76180013..69328a41 100644
--- a/src/os/darwin/darwin_sigar.c
+++ b/src/os/darwin/darwin_sigar.c
@@ -1756,6 +1756,7 @@ int sigar_net_interface_config_get(sigar_t *sigar, const char *name,
     ifm = iter.data.ifm;
 
     SIGAR_SSTRCPY(ifconfig->name, name);
+    ifconfig->speed = SIGAR_FIELD_NOTIMPL;
 
     sdl = (struct sockaddr_dl *)(ifm + 1);
     sigar_hwaddr_format(ifconfig->hwaddr,
diff --git a/src/os/win32/win32_sigar.c b/src/os/win32/win32_sigar.c
index 050331a4..b66fb672 100644
--- a/src/os/win32/win32_sigar.c
+++ b/src/os/win32/win32_sigar.c
@@ -1981,6 +1981,7 @@ int sigar_get_ifentry_config(sigar_t *sigar,
     }
 
     ifconfig->mtu = ifr->dwMtu;
+    ifconfig->speed = ifr->dwSpeed;
 
     sigar_hwaddr_format(ifconfig->hwaddr,
                         ifr->bPhysAddr);
diff --git a/src/sigar.c b/src/sigar.c
index 23cfbc4d..d582272b 100644
--- a/src/sigar.c
+++ b/src/sigar.c
@@ -1206,6 +1206,7 @@ int sigar_net_interface_config_get(sigar_t *sigar, const char *name,
 
     SIGAR_SSTRCPY(ifconfig->name, name);
     SIGAR_SSTRCPY(ifr.ifr_name, name);
+    ifconfig->speed = SIGAR_FIELD_NOTIMPL;
 
 #define ifr_s_addr(ifr) \
     ((struct sockaddr_in *)&ifr.ifr_addr)->sin_addr.s_addr
diff --git a/src/sigar_win32ish.c b/src/sigar_win32ish.c
index 329170c5..64b83d04 100644
--- a/src/sigar_win32ish.c
+++ b/src/sigar_win32ish.c
@@ -255,6 +255,8 @@ sigar_net_interface_config_get(sigar_t *sigar,
      */
     SIGAR_SSTRCPY(ifconfig->description,
                   ifconfig->name);
+    
+    ifconfig->speed = SIGAR_FIELD_NOTIMPL;
 
     hwaddr_lookup(sigar, ifconfig, i);