diff --git a/tests/test_functions.sh b/tests/test_functions.sh
index 126080f..4d0237a 100755
--- a/tests/test_functions.sh
+++ b/tests/test_functions.sh
@@ -13,26 +13,26 @@
 
 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