diff --git a/libnetutils/dhcpclient.c b/libnetutils/dhcpclient.c
index b38e258..34500e7 100644
--- a/libnetutils/dhcpclient.c
+++ b/libnetutils/dhcpclient.c
@@ -197,7 +197,11 @@
         }
         switch(opt) {
         case OPT_SUBNET_MASK:
-            if (optlen >= 4) info->prefixLength = ipv4NetmaskToPrefixLength(*((uint32_t*)x));
+            if (optlen >= 4) {
+                in_addr_t mask;
+                memcpy(&mask, x, 4);
+                info->prefixLength = ipv4NetmaskToPrefixLength(mask);
+            }
             break;
         case OPT_GATEWAY:
             if (optlen >= 4) memcpy(&info->gateway, x, 4);