diff --git a/net/utils/net_ipv6_mask2pref.c b/net/utils/net_ipv6_mask2pref.c
index 7800900d63..562fe40f12 100644
--- a/net/utils/net_ipv6_mask2pref.c
+++ b/net/utils/net_ipv6_mask2pref.c
@@ -39,9 +39,6 @@
 
 #include <nuttx/config.h>
 
-#include <stdint.h>
-#include <arpa/inet.h>
-
 #include "utils/utils.h"
 
 #ifdef CONFIG_NET_IPv6
@@ -71,7 +68,7 @@ static const uint8_t g_nibblemap[16] =
 
 static inline uint8_t net_msbits4(uint8_t nibble)
 {
-  /* Return the number of leading zeroes: 0-4) */
+  /* Return the number of leading ones: 0-4) */
 
   return g_nibblemap[nibble];
 }
diff --git a/net/utils/net_ipv6_maskcmp.c b/net/utils/net_ipv6_maskcmp.c
index 34d86e11ee..e8f7e007b6 100644
--- a/net/utils/net_ipv6_maskcmp.c
+++ b/net/utils/net_ipv6_maskcmp.c
@@ -41,8 +41,6 @@
 
 #include <nuttx/net/ip.h>
 
-#include "utils/utils.h"
-
 #ifdef CONFIG_NET_IPv6
 
 /****************************************************************************
diff --git a/net/utils/net_ipv6_pref2mask.c b/net/utils/net_ipv6_pref2mask.c
index 56dc44471a..f7521f6c12 100644
--- a/net/utils/net_ipv6_pref2mask.c
+++ b/net/utils/net_ipv6_pref2mask.c
@@ -101,12 +101,12 @@ void net_ipv6_pref2mask(uint8_t preflen, net_ipv6addr_t mask)
           else
             {
               /* Eg. preflen = 38, bit = {32}
-               *     bit - preflen = 6
+               *     preflen - bit = 6
                *     mask = 0xffff << (16-6)
                *          = 0xfc00
                */
 
-              mask[i]  = 0xffff << (16 - (bit - preflen));
+              mask[i] = 0xffff << (16 - (preflen - bit));
             }
         }
       else