diff --git a/os/connection.c b/os/connection.c
index bc35a60..68bdf43 100644
--- a/os/connection.c
+++ b/os/connection.c
@@ -122,6 +122,7 @@ int	       	*ListenTransFds = NULL;
 int		ListenTransCount;
 
 
+extern int  xfd_ffs (fd_mask);
 static void error_conn_max(XtransConnInfo trans_conn);
 static void close_fd(OsCommPtr oc);
 
@@ -316,7 +318,7 @@ MakeNewConnections(void)
 	XtransConnInfo trans_conn, new_trans_conn;
 	int status;
 
-	curconn = ffs(readyconnections) - 1;
+	curconn = xfd_ffs(readyconnections) - 1;
 	readyconnections &= ~(1 << curconn);
 
 	if ((trans_conn = lookup_trans_conn (curconn)) == NULL)
@@ -454,7 +456,7 @@ CheckConnections(void)
     XFD_COPYSET(&AllClients, &mask);
     for (i = 0; i < howmany(XFD_SETSIZE, NFDBITS); i++) {
 	while (mask.fds_bits[i]) {
-	    curclient = ffs(mask.fds_bits[i]) - 1 + (i << 5);
+	    curclient = xfd_ffs(mask.fds_bits[i]) - 1 + (i * (sizeof(fd_mask) * 8));
 	    FD_ZERO(&tmask);
 	    FD_SET(curclient, &tmask);
 	    r = Select(curclient + 1, &tmask, NULL, NULL, &notime);
diff --git a/os/io.c b/os/io.c
index 13c7fe4..8d9659a 100644
--- a/os/io.c
+++ b/os/io.c
@@ -86,6 +86,7 @@ static ConnectionInputPtr FreeInputs = (ConnectionInputPtr) NULL;
 static ConnectionOutputPtr FreeOutputs = (ConnectionOutputPtr) NULL;
 static OsCommPtr AvailableInput = (OsCommPtr) NULL;
 
+extern int xfd_ffs(fd_mask);
 static ConnectionInputPtr AllocateInputBuffer(void);
 static ConnectionOutputPtr AllocateOutputBuffer(void);
 
@@ -524,9 +525,9 @@ FlushAllOutput(void)
 	mask = OutputPending.fds_bits[base];
 	OutputPending.fds_bits[base] = 0;
 	while (mask) {
-	    index = ffs(mask) - 1;
+	    index = xfd_ffs(mask) - 1;
 	    mask &= ~lowbit(mask);
-	    if ((index = ConnectionTranslation[(base << 5) + index]) == 0)
+	    if ((index = ConnectionTranslation[(base * (sizeof(fd_mask) * 8)) + index]) == 0)
 		continue;
 	    client = clients[index];
 	    if (client->clientGone == CLIENT_GONE)
diff --git a/os/waitfor.c b/os/waitfor.c
index 1a29a97..4e80eba 100644
--- a/os/waitfor.c
+++ b/os/waitfor.c
@@ -67,10 +67,12 @@ in this Software without prior written authorization from The Open Group.
 #endif
 
 long        LastReapTime;
+int         xfd_ffs(fd_mask);
+
 
 /* like ffs, but uses fd_mask instead of int as argument, so it works
    when fd_mask is longer than an int, such as common 64-bit platforms */
-static inline int
+int
 xfd_ffs(fd_mask mask)
 {
     int i;
@@ -195,7 +197,7 @@ WaitForSomething(int *pClientsReady)
 	for (i = 0; i < howmany(XFD_SETSIZE, NFDBITS); i++) {
 	    while (clientsReadable.fds_bits[i]) {
 		curclient = xfd_ffs(clientsReadable.fds_bits[i]) - 1;
-		conn = ConnectionTranslation[curclient + (i << 5)];
+		conn = ConnectionTranslation[curclient + (i * (sizeof(fd_mask) * 8))];
 		clientsReadable.fds_bits[i] &= ~(((fd_mask)1L) << curclient);
 		client = clients[conn];
 		if (!client)