diff --git a/Lib/test/test_grammar.py b/Lib/test/test_grammar.py
index 4352275..d4bcfda 100644
--- a/Lib/test/test_grammar.py
+++ b/Lib/test/test_grammar.py
@@ -572,6 +572,15 @@
         while 0: pass
         else: pass
 
+        # Issue1920: "while 0" is optimized away,
+        # ensure that the "else" clause is still present.
+        x = 0
+        while 0:
+            x = 1
+        else:
+            x = 2
+        self.assertEquals(x, 2)
+
     def testFor(self):
         # 'for' exprlist 'in' exprlist ':' suite ['else' ':' suite]
         for i in 1, 2, 3: pass