diff --git slock.c slock.c
index a00fbb9..f24fd21 100644
--- slock.c
+++ slock.c
@@ -127,6 +127,7 @@ readpw(Display *dpy, const char *pws)
 	KeySym ksym;
 	XEvent ev;
 	static int oldc = INIT;
+	int seenkeypress = 0;
 
 	len = 0;
 	running = True;
@@ -136,9 +137,14 @@ readpw(Display *dpy, const char *pws)
 	 * utility. This way the user can easily set a customized DPMS
 	 * timeout. */
 	while (running && !XNextEvent(dpy, &ev)) {
-		if (ev.type == KeyPress) {
+		if (ev.type == KeyPress || ev.type == KeyRelease) {
 			explicit_bzero(&buf, sizeof(buf));
 			num = XLookupString(&ev.xkey, buf, sizeof(buf), &ksym, 0);
+			seenkeypress |= ev.type == KeyPress;
+			if ((ev.type == KeyRelease && (num || !seenkeypress)) ||
+			    (ev.type == KeyPress && !num)) {
+				continue;
+			}
 			if (IsKeypadKey(ksym)) {
 				if (ksym == XK_KP_Enter)
 					ksym = XK_Return;