--- a/display.c
+++ b/display.c
@@ -5,6 +5,7 @@
  * hints that are left in the windows by the commands
  */
 
+#include <stdlib.h>
 #include <string.h>
 #include "estruct.h"
 #include "edef.h"
@@ -100,7 +101,6 @@
 void vtinit ()
 {
   VIDEO *vp;
-  char *malloc ();
   int i;
 
   (*term.t_open) ();
--- a/line.c
+++ b/line.c
@@ -47,7 +47,6 @@
 {
   LINE *lp;
   int size;
-  char *malloc ();
 
   size = (used + NBLOCK - 1) & ~(NBLOCK - 1);
   if (size == 0)	       /* Assume that an empty */
@@ -469,8 +468,6 @@
  */
 int kinsert (int c)
 {
-  char *realloc ();
-  char *malloc ();
   char *nbufp;
 
   if (kused == ksize)
--- a/tcap.c
+++ b/tcap.c
@@ -2,6 +2,7 @@
 
 #define	termdef	1		/* don't define "term" external */
 
+#include <stdlib.h>
 #include <stdio.h>		/* puts(3), snprintf(3) */
 #include "estruct.h"
 #include "edef.h"
--- a/termio.c
+++ b/termio.c
@@ -5,6 +5,7 @@
  */
 
 #undef CTRL
+#include <stdlib.h>
 #include <termios.h>
 #include <unistd.h>
 #include <signal.h>