Index: doctest.py
===================================================================
--- doctest.py	(revision 59247)
+++ doctest.py	(working copy)
@@ -2646,6 +2646,7 @@
            }
 
 def _test():
+    passed = 1
     testfiles = [arg for arg in sys.argv[1:] if arg and arg[0] != '-']
     if testfiles:
         for filename in testfiles:
@@ -2657,12 +2658,18 @@
                 sys.path.insert(0, dirname)
                 m = __import__(filename[:-3])
                 del sys.path[0]
-                testmod(m)
+                failures, tries = testmod(m)
             else:
-                testfile(filename, module_relative=False)
+                failures, tries = testfile(filename, module_relative=False)
+            if failures:
+                passed = 0
     else:
         r = unittest.TextTestRunner()
         r.run(DocTestSuite())
 
+    return passed
+
 if __name__ == "__main__":
-    _test()
+    passed = _test()
+    if not passed:
+        raise SystemExit(1)