diff --git a/dmenu.c b/dmenu.c
index efc1e54..c25dc82 100644
--- a/dmenu.c
+++ b/dmenu.c
@@ -392,7 +392,8 @@ keypress(XKeyEvent *ev) {
 	case XK_Tab:
 		if(!sel)
 			return;
-		strncpy(text, sel->text, sizeof text);
+		strncpy(text, sel->text, sizeof text - 1);
+		text[sizeof text - 1] = '\0';
 		cursor = strlen(text);
 		match();
 		break;