diff --git a/include/empio.h b/include/empio.h
index 70237ebc..5698c721 100644
--- a/include/empio.h
+++ b/include/empio.h
@@ -42,9 +42,6 @@
 
 #define IO_BUFSIZE	4096
 
-#define IO_NOWAIT	0
-#define IO_WAIT		1
-
 extern struct iop *io_open(int, int, int, struct timeval);
 extern void io_init(void);
 extern void io_close(struct iop *);
diff --git a/src/lib/empthread/io.c b/src/lib/empthread/io.c
index 8b47bbc6..f2a22704 100644
--- a/src/lib/empthread/io.c
+++ b/src/lib/empthread/io.c
@@ -183,15 +183,14 @@ io_outputwaiting(struct iop *iop)
 
 /*
  * Write output queued in IOP.
- * If WAITFOROUTPUT != IO_NOWAIT, writing may put the thread to sleep.
+ * If WAIT, writing may put the thread to sleep.
  * Return number of bytes written on success, -1 on error.
  * In particular, return zero when nothing was written because the
  * queue was empty, or because the write slept and got woken up (only
- * if WAITFOROUTPUT != IO_NOWAIT), or because the write refused to
- * sleep (only if WAITFOROUTPUT == IO_NOWAIT).
+ * if WAIT), or because the write refused to sleep (only if !WAIT).
  */
 int
-io_output(struct iop *iop, int waitforoutput)
+io_output(struct iop *iop, int wait)
 {
     struct iovec iov[16];
     int n, res, cc;
@@ -207,7 +206,7 @@ io_output(struct iop *iop, int waitforoutput)
 
     n = ioq_makeiov(iop->output, iov, IO_BUFSIZE);
 
-    if (waitforoutput != IO_NOWAIT) {
+    if (wait) {
 	res = empth_select(iop->fd, EMPTH_FD_WRITE, NULL);
 	if (res == 0)
 	    return 0;
@@ -251,7 +250,7 @@ io_read(struct iop *iop, char *buf, int nbytes)
 }
 
 int
-io_write(struct iop *iop, char *buf, int nbytes, int doWait)
+io_write(struct iop *iop, char *buf, int nbytes, int wait)
 {
     int len;
 
@@ -260,12 +259,12 @@ io_write(struct iop *iop, char *buf, int nbytes, int doWait)
     ioq_append(iop->output, buf, nbytes);
     len = ioq_qsize(iop->output);
     if (len > iop->bufsize) {
-	if (doWait) {
+	if (wait) {
 	    io_output_all(iop);
 	} else {
 	    /* only try a write every BUFSIZE characters */
 	    if (((len - nbytes) % iop->bufsize) < (len % iop->bufsize))
-		io_output(iop, IO_NOWAIT);
+		io_output(iop, 0);
 	}
     }
     return nbytes;
@@ -280,7 +279,7 @@ io_output_all(struct iop *iop)
      * Mustn't block a player thread while update is pending, or else
      * a malicous player could delay the update indefinitely
      */
-    while ((n = io_output(iop, IO_NOWAIT)) > 0 && !play_wrlock_wanted)
+    while ((n = io_output(iop, 0)) > 0 && !play_wrlock_wanted)
 	empth_select(iop->fd, EMPTH_FD_WRITE, NULL);
 
     return n;
diff --git a/src/lib/player/login.c b/src/lib/player/login.c
index 16f27ad1..2cad2d1d 100644
--- a/src/lib/player/login.c
+++ b/src/lib/player/login.c
@@ -87,9 +87,9 @@ player_login(void *ud)
     pr_id(player, C_INIT, "Empire server ready\n");
 
     while (player->state != PS_SHUTDOWN) {
-	io_output(player->iop, IO_WAIT);
+	io_output(player->iop, 1);
 	if (io_gets(player->iop, buf, sizeof(buf)) < 0) {
-	    res = io_input(player->iop, IO_WAIT);
+	    res = io_input(player->iop, 1);
 	    if (res <= 0) {
 		if (res == 0 && !io_eof(player->iop))
 		    pr_id(player, C_DATA, "idle connection terminated\n");
@@ -118,7 +118,7 @@ player_login(void *ud)
     player->state = PS_SHUTDOWN;
     if (!io_eof(player->iop)) {
 	pr_id(player, C_EXIT, "so long...\n");
-	while (io_output(player->iop, IO_WAIT) > 0) ;
+	while (io_output(player->iop, 1) > 0) ;
     }
     player_delete(player);
     empth_exit();
diff --git a/src/lib/player/recvclient.c b/src/lib/player/recvclient.c
index 06ab8ae7..cd954b2a 100644
--- a/src/lib/player/recvclient.c
+++ b/src/lib/player/recvclient.c
@@ -85,7 +85,7 @@ recvclient(char *cmd, int size)
 	if (player->aborted)
 	    break;
 
-	res = io_input(player->iop, IO_WAIT);
+	res = io_input(player->iop, 1);
 	if (res > 0)
 	    ;
 	else if (res < 0)
diff --git a/src/lib/subs/pr.c b/src/lib/subs/pr.c
index 79fbd1d7..42ae1bc2 100644
--- a/src/lib/subs/pr.c
+++ b/src/lib/subs/pr.c
@@ -152,7 +152,7 @@ pr_flash(struct player *pl, char *format, ...)
     if (!(pl->flags & PF_UTF8))
 	copy_utf8_to_ascii_no_funny(buf, buf);
     pr_player(pl, C_FLASH, buf);
-    io_output(pl->iop, IO_NOWAIT);
+    io_output(pl->iop, 0);
 }
 
 /*
@@ -173,7 +173,7 @@ pr_inform(struct player *pl, char *format, ...)
     (void)vsprintf(buf, format, ap);
     va_end(ap);
     pr_player(pl, C_INFORM, buf);
-    io_output(pl->iop, IO_NOWAIT);
+    io_output(pl->iop, 0);
 }
 
 /*
@@ -205,7 +205,7 @@ pr_wall(char *format, ...)
 	if (p->state != PS_PLAYING)
 	    continue;
 	pr_player(p, C_FLASH, buf);
-	io_output(p->iop, IO_NOWAIT);
+	io_output(p->iop, 0);
     }
 }
 
@@ -233,11 +233,9 @@ pr_player(struct player *pl, int id, char *buf)
 	p = strchr(bp, '\n');
 	if (p != NULL) {
 	    len = (p - bp) + 1;
-	    if ((pl->command && (pl->command->c_flags & C_MOD)) ||
-		(player != pl))
-		io_write(pl->iop, bp, len, IO_NOWAIT);
-	    else
-		io_write(pl->iop, bp, len, IO_WAIT);
+	    io_write(pl->iop, bp, len,
+		     player == pl
+		     && !(pl->command && (pl->command->c_flags & C_MOD)));
 	    bp += len;
 	    pl->curid = -1;
 	} else {
@@ -288,11 +286,9 @@ upr_player(struct player *pl, int id, char *buf)
 	    }
 	}
 	if (ch == '\n') {
-	    if ((pl->command && (pl->command->c_flags & C_MOD)) ||
-		(player != pl))
-		io_write(pl->iop, &ch, 1, IO_NOWAIT);
-	    else
-		io_write(pl->iop, &ch, 1, IO_WAIT);
+	    io_write(pl->iop, &ch, 1,
+		     player == pl
+		     && !(pl->command && (pl->command->c_flags & C_MOD)));
 	    pl->curid = -1;
 	} else {
 	    printbuf[0] = ch;