diff --git a/tests/test_functions.sh b/tests/test_functions.sh
index 126080f1e3..4d0237afb7 100755
--- a/tests/test_functions.sh
+++ b/tests/test_functions.sh
@@ -13,26 +13,26 @@ source $TOP/openrc
 
 echo "Testing die_if_not_set()"
 
-bash -cx "source $TOP/functions; X=`echo Y && true`; die_if_not_set X 'not OK'"
+bash -c "source $TOP/functions; X=`echo Y && true`; die_if_not_set $LINENO X 'not OK'"
 if [[ $? != 0 ]]; then
 echo "die_if_not_set [X='Y' true] Failed"
 else
 echo 'OK'
 fi
 
-bash -cx "source $TOP/functions; X=`true`; die_if_not_set X 'OK'"
+bash -c "source $TOP/functions; X=`true`; die_if_not_set $LINENO X 'OK'"> /dev/null 2>&1
 if [[ $? = 0 ]]; then
 echo "die_if_not_set [X='' true] Failed"
 fi
 
-bash -cx "source $TOP/functions; X=`echo Y && false`; die_if_not_set X 'not OK'"
+bash -c "source $TOP/functions; X=`echo Y && false`; die_if_not_set $LINENO X 'not OK'"
 if [[ $? != 0 ]]; then
 echo "die_if_not_set [X='Y' false] Failed"
 else
 echo 'OK'
 fi
 
-bash -cx "source $TOP/functions; X=`false`; die_if_not_set X 'OK'"
+bash -c "source $TOP/functions; X=`false`; die_if_not_set $LINENO X 'OK'"> /dev/null 2>&1
 if [[ $? = 0 ]]; then
 echo "die_if_not_set [X='' false] Failed"
 fi
</div><div class="naked_ctrl">
<form action="/index.cgi/speech" method="get" name="gate">
<p><a href="http://altstyle.alfasado.net">AltStyle</a> によって変換されたページ <a href="https://opendev.org/openstack/devstack/commit/9b845da478ae2fb65ac63de95f6005ecacbb52ce.diff">(-&gt;オリジナル)</a>
/ <label>アドレス: <input type="text" name="naked_post_url" value="https://opendev.org/openstack/devstack/commit/9b845da478ae2fb65ac63de95f6005ecacbb52ce.diff" size="22" /></label> <label>モード: <select name="naked_post_mode">
<option value="default">デフォルト</option>
<option value="speech" selected="selected">音声ブラウザ</option>
<option value="ruby">ルビ付き</option>
<option value="contrast">配色反転</option>
<option value="larger-text">文字拡大</option>
<option value="mobile">モバイル</option>
</select>
<input type="submit" value="表示" />
</p>
</form>
</div>