diff --git a/t/sandbox b/t/sandbox
index c460da11..693124db 100755
--- a/t/sandbox
+++ b/t/sandbox
@@ -3,9 +3,6 @@
 [ -e tests.sh ] && . ./tests.sh || . ../tests.sh
 
 NAME='sandbox disable'
-IGNORE_ERR=1
-FILE=-
-ARGS=
 CMDS='e cfg.sandbox=true
 e cfg.sandbox=false
 e cfg.sandbox
@@ -13,3 +10,12 @@ e cfg.sandbox
 EXPECT='true
 '
 run_test
+
+NAME='sandbox open'
+CMDS='e cfg.sandbox=true
+o~[2]
+oc /bin/ls
+'
+EXPECT='malloc://512
+'
+run_test