diff --git a/tests/data/iter_read_generator.py b/tests/data/iter_read_generator.py
new file mode 100755
index 00000000..3fd3c08c
--- /dev/null
+++ b/tests/data/iter_read_generator.py
@@ -0,0 +1,13 @@
+#!/usr/bin/env python
+# I produce text every 100ms, for testing mitogen.core.iter_read()
+
+import sys
+import time
+
+
+i = 0
+while True:
+    i += 1
+    sys.stdout.write(str(i))
+    sys.stdout.flush()
+    time.sleep(0.1)
diff --git a/tests/data/iter_read_generator.sh b/tests/data/iter_read_generator.sh
deleted file mode 100755
index 3aa6d6ac..00000000
--- a/tests/data/iter_read_generator.sh
+++ /dev/null
@@ -1,10 +0,0 @@
-#!/bin/bash
-# I produce text every 100ms, for testing mitogen.core.iter_read()
-
-i=0
-
-while :; do
-    i=$(($i + 1))
-    echo "$i"
-    sleep 0.1
-done
diff --git a/tests/parent_test.py b/tests/parent_test.py
index aaf335b8..c0c542f4 100644
--- a/tests/parent_test.py
+++ b/tests/parent_test.py
@@ -215,7 +215,7 @@ class IterReadTest(unittest2.TestCase):
     func = staticmethod(mitogen.parent.iter_read)
 
     def make_proc(self):
-        args = [testlib.data_path('iter_read_generator.sh')]
+        args = [testlib.data_path('iter_read_generator.py')]
         proc = subprocess.Popen(args, stdout=subprocess.PIPE)
         mitogen.core.set_nonblock(proc.stdout.fileno())
         return proc