diff --git a/dlls/iphlpapi/iphlpapi_main.c b/dlls/iphlpapi/iphlpapi_main.c
index 88db25a3f85..4d187111534 100644
--- a/dlls/iphlpapi/iphlpapi_main.c
+++ b/dlls/iphlpapi/iphlpapi_main.c
@@ -983,6 +983,7 @@ static ULONG adapterAddressesFromIndex(ULONG family, ULONG flags, IF_INDEX index
                 struct WS_sockaddr_in6 *sa;
                 const IN6_ADDR *addr, *mask;
                 BOOL done = FALSE;
+                ULONG k;
 
                 prefix->u.s.Length = sizeof(*prefix);
                 prefix->u.s.Flags  = 0;
@@ -1000,11 +1001,11 @@ static ULONG adapterAddressesFromIndex(ULONG family, ULONG flags, IF_INDEX index
                 sa->sin6_scope_id = 0;
 
                 prefix->PrefixLength = 0;
-                for (i = 0; i < 8 && !done; i++)
+                for (k = 0; k < 8 && !done; k++)
                 {
                     for (j = 0; j < sizeof(WORD) * 8 && !done; j++)
                     {
-                        if (mask->u.Word[i] & 1 << j) prefix->PrefixLength++;
+                        if (mask->u.Word[k] & 1 << j) prefix->PrefixLength++;
                         else done = TRUE;
                     }
                 }