diff --git a/Lib/test/test_threadsignals.py b/Lib/test/test_threadsignals.py
index 14bd3b7..7959e91 100644
--- a/Lib/test/test_threadsignals.py
+++ b/Lib/test/test_threadsignals.py
@@ -5,10 +5,10 @@
 import signal
 import os
 import sys
-from test.support import run_unittest, TestSkipped
+from test.support import run_unittest
 
-if sys.platform[:3] in ('win', 'os2'):
-    raise TestSkipped("Can't test signal on %s" % sys.platform)
+if sys.platform[:3] in ('win', 'os2') or sys.platform=='riscos':
+    raise unittest.SkipTest("Can't test signal on %s" % sys.platform)
 
 process_pid = os.getpid()
 signalled_all=thread.allocate_lock()