diff --git a/Source/NSRunLoop.m b/Source/NSRunLoop.m
index e429de2c0..acb90a3c5 100644
--- a/Source/NSRunLoop.m
+++ b/Source/NSRunLoop.m
@@ -72,10 +72,6 @@
 #include <limits.h>
 #include <string.h>		/* for memset() */
 
-/* On some systems FD_ZERO is a macro that uses bzero().
-   Just define it to use memset(). */
-#define bzero(PTR, LEN) memset (PTR, 0, LEN)
-
 static int debug_run_loop = 0;
 
 /*
@@ -1089,8 +1085,8 @@ static int debug_run_loop = 0;
      Initialize the set of FDS we'll pass to select(), and create
      an empty map for keeping track of which object is associated
      with which file descriptor. */
-  FD_ZERO (&fds);
-  FD_ZERO (&write_fds);
+  memset(&fds, '\0', sizeof(fds));
+  memset(&write_fds, '\0', sizeof(write_fds));
   rfd_2_object = NSCreateMapTable (NSIntMapKeyCallBacks,
 				  NSObjectMapValueCallBacks, 0);
   wfd_2_object = NSCreateMapTable (NSIntMapKeyCallBacks,
diff --git a/Source/TcpPort.m b/Source/TcpPort.m
index 2012632ec..949252486 100644
--- a/Source/TcpPort.m
+++ b/Source/TcpPort.m
@@ -83,10 +83,6 @@
 #include <sys/errno.h>
 #endif /* !__WIN32__ */
 
-/* On some systems FD_ZERO is a macro that uses bzero().
-   Just define it to use GCC's builtin memset(). */
-#define bzero(PTR, LEN) memset (PTR, 0, LEN)
-
 static int debug_tcp_port = 0;
 
 
@@ -204,7 +200,7 @@ tryRead(int desc, int tim, unsigned char* dat, int len)
 
   for (;;) {
     to = &timeout;
-    FD_ZERO(&fds);
+    memset(&fds, '\0', sizeof(fds));
     FD_SET(desc, &fds);
 
     rval = select(FD_SETSIZE, &fds, 0, 0, to);
@@ -289,7 +285,7 @@ tryWrite(int desc, int tim, unsigned char* dat, int len)
 
   for (;;) {
     to = &timeout;
-    FD_ZERO(&fds);
+    memset(&fds, '\0', sizeof(fds));
     FD_SET(desc, &fds);
 
     rval = select(FD_SETSIZE, 0, &fds, 0, to);
diff --git a/Source/UdpPort.m b/Source/UdpPort.m
index 8e19af658..36cb338f8 100644
--- a/Source/UdpPort.m
+++ b/Source/UdpPort.m
@@ -224,7 +224,7 @@ static NSMapTable *port_number_2_in_port = NULL;
 
       timeout.tv_sec = milliseconds / 1000;
       timeout.tv_usec = (milliseconds % 1000) * 1000;
-      FD_ZERO(&ready);
+      memset(&ready, '\0', sizeof(ready));
       FD_SET(_port_socket, &ready);
       if ((r = select(_port_socket + 1, &ready, 0, 0, &timeout)) < 0)
 	{