diff --git a/Lib/tokenize.py b/Lib/tokenize.py
index ec9f63c..ca4dbf0 100644
--- a/Lib/tokenize.py
+++ b/Lib/tokenize.py
@@ -168,10 +168,7 @@
 
     def add_whitespace(self, start):
         row, col = start
-        while row > self.prev_row:
-            print row, "<", self.prev_row
-            self.tokens.append("\n")
-            self.prev_row += 1
+        assert row <= self.prev_row
         col_offset = col - self.prev_col
         if col_offset:
             self.tokens.append(" " * col_offset)