diff --git a/core/net/uiplib.c b/core/net/uiplib.c
index 0bf35b039..7ca55bb36 100644
--- a/core/net/uiplib.c
+++ b/core/net/uiplib.c
@@ -57,13 +57,13 @@ uiplib_ipaddrconv(const char *addrstr, uip_ipaddr_t *ipaddr)
 
   for(len = 0; len < sizeof(uip_ipaddr_t) - 1; addrstr++) {
     c = *addrstr;
-    if(c == ':' || c == '\0' || c == ']') {
+    if(c == ':' || c == '\0' || c == ']' || c == '/') {
       ipaddr->u8[len] = (value >> 8) & 0xff;
       ipaddr->u8[len + 1] = value & 0xff;
       len += 2;
       value = 0;
 
-      if(c == '\0' || c == ']') {
+      if(c == '\0' || c == ']' || c == '/') {
         break;
       }
 
@@ -88,7 +88,7 @@ uiplib_ipaddrconv(const char *addrstr, uip_ipaddr_t *ipaddr)
       value = (value << 4) + (tmp & 0xf);
     }
   }
-  if(c != '\0' && c != ']') {
+  if(c != '\0' && c != ']' && c != '/') {
     PRINTF("uiplib: too large address\n");
     return 0;
   }