diff --git a/winsup/cygwin/fhandler/socket.cc b/winsup/cygwin/fhandler/socket.cc
index f7c5ff629..c0cef7d3e 100644
--- a/winsup/cygwin/fhandler/socket.cc
+++ b/winsup/cygwin/fhandler/socket.cc
@@ -86,7 +86,7 @@ struct __old_ifreq {
 int
 fhandler_socket::ioctl (unsigned int cmd, void *p)
 {
-  extern int get_ifconf (struct ifconf *ifc, int what); /* net.cc */
+  extern int get_ifconf (struct ifconf *ifc, unsigned int what); /* net.cc */
   int res;
   struct ifconf ifc, *ifcp;
   struct ifreq *ifrp;
diff --git a/winsup/cygwin/net.cc b/winsup/cygwin/net.cc
index 08c584fe5..737e494f8 100644
--- a/winsup/cygwin/net.cc
+++ b/winsup/cygwin/net.cc
@@ -1912,7 +1912,7 @@ freeifaddrs (struct ifaddrs *ifp)
 }
 
 int
-get_ifconf (struct ifconf *ifc, int what)
+get_ifconf (struct ifconf *ifc, unsigned int what)
 {
   __try
     {