diff --git a/tools/test-harness/xpcshell-simple/test_all.sh b/tools/test-harness/xpcshell-simple/test_all.sh
index 91caff80284a..635506ddcb85 100755
--- a/tools/test-harness/xpcshell-simple/test_all.sh
+++ b/tools/test-harness/xpcshell-simple/test_all.sh
@@ -110,7 +110,7 @@ done
 for t in $testdir/test_*.js
 do
     echo -n "$t: "
-    NATIVE_TOPSRCDIR="$native_topsrcdir" TOPSRCDIR="$topsrcdir" $xpcshell $headfiles -f $t $tailfiles 2> $t.log 1>&2
+    NATIVE_TOPSRCDIR="$native_topsrcdir" TOPSRCDIR="$topsrcdir" $xpcshell -s $headfiles -f $t $tailfiles 2> $t.log 1>&2
     if [ `grep -c '\*\*\* PASS' $t.log` = 0 ]
     then
         echo "FAIL"