diff --git a/test/mitmproxy/data/addonscripts/concurrent_decorator_class.py b/test/mitmproxy/data/addonscripts/concurrent_decorator_class.py
new file mode 100644
index 000000000..bd047c99a
--- /dev/null
+++ b/test/mitmproxy/data/addonscripts/concurrent_decorator_class.py
@@ -0,0 +1,13 @@
+import time
+from mitmproxy.script import concurrent
+
+
+class ConcurrentClass:
+
+    @concurrent
+    def request(flow):
+        time.sleep(0.1)
+
+
+def start():
+    return ConcurrentClass()
diff --git a/test/mitmproxy/script/test_concurrent.py b/test/mitmproxy/script/test_concurrent.py
index fb932d9a2..e81c023dd 100644
--- a/test/mitmproxy/script/test_concurrent.py
+++ b/test/mitmproxy/script/test_concurrent.py
@@ -44,3 +44,21 @@ class TestConcurrent(tservers.MasterTest):
             )
             sc.start()
             assert "decorator not supported" in tctx.master.event_log[0][1]
+
+    def test_concurrent_class(self):
+            with taddons.context() as tctx:
+                sc = script.Script(
+                    tutils.test_data.path(
+                        "mitmproxy/data/addonscripts/concurrent_decorator_class.py"
+                    )
+                )
+                sc.start()
+
+                f1, f2 = tflow.tflow(), tflow.tflow()
+                tctx.cycle(sc, f1)
+                tctx.cycle(sc, f2)
+                start = time.time()
+                while time.time() - start < 5:
+                    if f1.reply.state == f2.reply.state == "committed":
+                        return
+                raise ValueError("Script never acked")