diff --git a/src/testdir/test86.in b/src/testdir/test86.in
index 1309643..71635bd 100644
--- a/src/testdir/test86.in
+++ b/src/testdir/test86.in
@@ -267,6 +267,54 @@
 :      $put =toput
 :   endtry
 :endfor
+:"
+:" threading
+:let l = [0]
+:py l=vim.bindeval('l')
+:py <<EOF
+import threading
+import time
+
+class T(threading.Thread):
+    def __init__(self):
+        threading.Thread.__init__(self)
+        self.t = 0
+        self.running = True
+
+    def run(self):
+        while self.running:
+            self.t += 1
+            time.sleep(0.1)
+
+t = T()
+t.start()
+EOF
+:sleep 1
+:py t.running = False
+:py t.join()
+:py l[0] = t.t > 8  # check if the background thread is working
+:$put =string(l)
+:"
+:" settrace
+:let l = []
+:py l=vim.bindeval('l')
+:py <<EOF
+import sys
+
+def traceit(frame, event, arg):
+    global l
+    if event == "line":
+        l.extend([frame.f_lineno])
+    return traceit
+
+def trace_main():
+    for i in range(5):
+        pass
+EOF
+:py sys.settrace(traceit)
+:py trace_main()
+:py sys.settrace(None)
+:$put =string(l)
 :endfun
 :"
 :call Test()