diff --git a/tests/data/write_all_consumer.py b/tests/data/write_all_consumer.py
new file mode 100755
index 00000000..4013ccdd
--- /dev/null
+++ b/tests/data/write_all_consumer.py
@@ -0,0 +1,9 @@
+#!/usr/bin/env python
+# I consume 65535 bytes every 10ms, for testing mitogen.core.write_all()
+
+import os
+import time
+
+while True:
+    os.read(0, 65535)
+    time.sleep(0.01)
diff --git a/tests/data/write_all_consumer.sh b/tests/data/write_all_consumer.sh
deleted file mode 100755
index e6aaaf72..00000000
--- a/tests/data/write_all_consumer.sh
+++ /dev/null
@@ -1,7 +0,0 @@
-#!/bin/bash
-# I consume 65535 bytes every 10ms, for testing mitogen.core.write_all()
-
-while :; do
-    read -n 65535
-    sleep 0.01
-done
diff --git a/tests/parent_test.py b/tests/parent_test.py
index 24327024..9d540ccc 100644
--- a/tests/parent_test.py
+++ b/tests/parent_test.py
@@ -267,7 +267,7 @@ class WriteAllTest(unittest2.TestCase):
     func = staticmethod(mitogen.parent.write_all)
 
     def make_proc(self):
-        args = [testlib.data_path('write_all_consumer.sh')]
+        args = [testlib.data_path('write_all_consumer.py')]
         proc = subprocess.Popen(args, stdin=subprocess.PIPE)
         mitogen.core.set_nonblock(proc.stdin.fileno())
         return proc