diff --git a/tools/testing/selftests/ftrace/test.d/filter/event-filter-function.tc b/tools/testing/selftests/ftrace/test.d/filter/event-filter-function.tc
index 118247b8dd84d..c62165fabd0ce 100644
--- a/tools/testing/selftests/ftrace/test.d/filter/event-filter-function.tc
+++ b/tools/testing/selftests/ftrace/test.d/filter/event-filter-function.tc
@@ -80,6 +80,26 @@ if [ $misscnt -gt 0 ]; then
 	exit_fail
 fi
 
+# Check strings too
+if [ -f events/syscalls/sys_enter_openat/filter ]; then
+	DIRNAME=`basename $TMPDIR`
+	echo "filename.ustring ~ \"*$DIRNAME*\"" > events/syscalls/sys_enter_openat/filter
+	echo 1 > events/syscalls/sys_enter_openat/enable
+	echo 1 > tracing_on
+	ls /bin/sh
+	nocnt=`grep openat trace | wc -l`
+	ls $TMPDIR
+	echo 0 > tracing_on
+	hitcnt=`grep openat trace | wc -l`;
+	echo 0 > events/syscalls/sys_enter_openat/enable
+	if [ $nocnt -gt 0 ]; then
+		exit_fail
+	fi
+	if [ $hitcnt -eq 0 ]; then
+		exit_fail
+	fi
+fi
+
 reset_events_filter
 
 exit 0