diff --git a/libnetutils/dhcpclient.c b/libnetutils/dhcpclient.c
index 5039e26..4f2d1c1 100644
--- a/libnetutils/dhcpclient.c
+++ b/libnetutils/dhcpclient.c
@@ -197,7 +197,7 @@
         }
         switch(opt) {
         case OPT_SUBNET_MASK:
-            if (optlen >= 4) info->prefixLength = ipv4NetmaskToPrefixLength((int)x);
+            if (optlen >= 4) info->prefixLength = ipv4NetmaskToPrefixLength(*((uint32_t*)x));
             break;
         case OPT_GATEWAY:
             if (optlen >= 4) memcpy(&info->gateway, x, 4);