diff --git a/st.c b/st.c
index 27536d2..5b18b58 100644
--- a/st.c
+++ b/st.c
@@ -45,6 +45,9 @@ char *argv0;
 #elif defined(__FreeBSD__) || defined(__DragonFly__)
  #include <libutil.h>
 #endif
+#ifndef __OpenBSD__
+int pledge(const char *promises, const char *paths[]) { return 0; }
+#endif
 
 
 /* XEMBED messages */
@@ -368,6 +371,7 @@ static void execsh(void);
 static void stty(void);
 static void sigchld(int);
 static void run(void);
+static void xpledge(const char *promises, const char *paths[]);
 
 static void csidump(void);
 static void csihandle(void);
@@ -4224,6 +4228,8 @@ run(void)
 	struct timespec drawtimeout, *tv = NULL, now, last, lastblink;
 	long deltatime;
 
+	xpledge("stdio rpath wpath tty proc getpw exec", NULL);
+
 	/* Waiting for window mapping */
 	do {
 		XNextEvent(xw.dpy, &ev);
@@ -4247,6 +4253,8 @@ run(void)
 	clock_gettime(CLOCK_MONOTONIC, &last);
 	lastblink = last;
 
+	xpledge("stdio rpath tty proc", NULL);
+
 	for (xev = actionfps;;) {
 		FD_ZERO(&rfd);
 		FD_SET(cmdfd, &rfd);
@@ -4336,6 +4344,14 @@ usage(void)
 	    " [stty_args ...]\n", argv0, argv0);
 }
 
+void
+xpledge(const char *promises, const char *paths[])
+{
+	if (pledge(promises, paths) < 0) {
+		die("st: pledge: %s (%s)\n", strerror(errno), promises);
+	}
+}
+
 int
 main(int argc, char *argv[])
 {