diff --git a/Lib/dummy_thread.py b/Lib/dummy_thread.py
index 7c26f9e..a72c927 100644
--- a/Lib/dummy_thread.py
+++ b/Lib/dummy_thread.py
@@ -79,8 +79,7 @@
 def stack_size(size=None):
     """Dummy implementation of thread.stack_size()."""
     if size is not None:
-        msg = "setting thread stack size not supported on this platform"
-        warnings.warn(msg, RuntimeWarning)
+        raise error("setting thread stack size not supported")
     return 0
 
 class LockType(object):
diff --git a/Lib/test/test_thread.py b/Lib/test/test_thread.py
index 7b523e2..7586ebc 100644
--- a/Lib/test/test_thread.py
+++ b/Lib/test/test_thread.py
@@ -133,7 +133,7 @@
         thread.stack_size(4096)
     except ValueError:
         print 'caught expected ValueError setting stack_size(4096)'
-    except thread.ThreadError:
+    except thread.error:
         tss_supported = 0
         print 'platform does not support changing thread stack size'