diff --git a/Lib/bisect.py b/Lib/bisect.py
index 688666a4116..4d92bc8e8aa 100644
--- a/Lib/bisect.py
+++ b/Lib/bisect.py
@@ -3,8 +3,9 @@
 
 # Insert item x in list a, and keep it sorted assuming a is sorted
 
-def insort(a, x):
-        lo, hi = 0, len(a)
+def insort(a, x, lo=0, hi=None):
+	if hi is None:
+		hi = len(a)
         while lo < hi:
 		mid = (lo+hi)/2
 		if x < a[mid]: hi = mid
@@ -14,8 +15,9 @@ def insort(a, x):
 
 # Find the index where to insert item x in list a, assuming a is sorted
 
-def bisect(a, x):
-        lo, hi = 0, len(a)
+def bisect(a, x, lo=0, hi=None):
+	if hi is None:
+		hi = len(a)
         while lo < hi:
 		mid = (lo+hi)/2
 		if x < a[mid]: hi = mid