diff --git a/Lib/test/test_decimal.py b/Lib/test/test_decimal.py
index 6da658f..7bfb13c 100644
--- a/Lib/test/test_decimal.py
+++ b/Lib/test/test_decimal.py
@@ -34,6 +34,13 @@
 from test.test_support import TestSkipped, run_unittest, run_doctest, is_resource_enabled
 import threading
 
+# Tests are built around these assumed context defaults
+DefaultContext.prec=9
+DefaultContext.rounding=ROUND_HALF_EVEN
+DefaultContext.trap_enablers=dict.fromkeys(Signals, 0)
+setcontext(DefaultContext)
+
+
 TESTDATADIR = 'decimaltestdata'
 if __name__ == '__main__':
     file = sys.argv[0]