diff --git a/src/lib/libc/stdlib/system.c b/src/lib/libc/stdlib/system.c
index 3e1b0473..dadf3fe8 100644
--- a/src/lib/libc/stdlib/system.c
+++ b/src/lib/libc/stdlib/system.c
@@ -32,7 +32,7 @@
  */
 
 #if defined(LIBC_SCCS) && !defined(lint)
-static char *rcsid = "$OpenBSD: system.c,v 1.3 1996/09/15 09:31:52 tholo Exp $";
+static char *rcsid = "$OpenBSD: system.c,v 1.4 2001/09/04 23:35:58 millert Exp $";
 #endif /* LIBC_SCCS and not lint */
 
 #include <sys/types.h>
@@ -50,7 +50,7 @@ system(command)
 {
 	pid_t pid;
 	sig_t intsave, quitsave;
-	int omask;
+	sigset_t mask, omask;
 	int pstat;
 	char *argp[] = {"sh", "-c", NULL, NULL};
 
@@ -59,13 +59,15 @@ system(command)
 
 	argp[2] = (char *)command;
 
-	omask = sigblock(sigmask(SIGCHLD));
+	sigemptyset(&mask);
+	sigaddset(&mask, SIGCHLD);
+	sigprocmask(SIG_BLOCK, &mask, &omask);
 	switch(pid = vfork()) {
 	case -1:			/* error */
-		(void)sigsetmask(omask);
+		sigprocmask(SIG_SETMASK, &omask, NULL);
 		return(-1);
 	case 0:				/* child */
-		(void)sigsetmask(omask);
+		sigprocmask(SIG_SETMASK, &omask, NULL);
 		execve(_PATH_BSHELL, argp, environ);
 		_exit(127);
 	}
@@ -73,7 +75,7 @@ system(command)
 	intsave = signal(SIGINT, SIG_IGN);
 	quitsave = signal(SIGQUIT, SIG_IGN);
 	pid = waitpid(pid, (int *)&pstat, 0);
-	(void)sigsetmask(omask);
+	sigprocmask(SIG_SETMASK, &omask, NULL);
 	(void)signal(SIGINT, intsave);
 	(void)signal(SIGQUIT, quitsave);
 	return(pid == -1 ? -1 : pstat);