diff --git a/src/evalfunc.c b/src/evalfunc.c
index 2377d19..0703b44 100644
--- a/src/evalfunc.c
+++ b/src/evalfunc.c
@@ -1930,6 +1930,9 @@
     char_u *opt = (char_u *)"";
     char_u buf[NUMBUFLEN];
 
+    /* Don't open a file in restricted mode. */
+    if (check_restricted() || check_secure())
+	return;
     fname = get_tv_string(&argvars[0]);
     if (argvars[1].v_type == VAR_STRING)
 	opt = get_tv_string_buf(&argvars[1], buf);