diff --git a/b64p.py b/b64p.py
index 781a4c8..6007453 100644
--- a/b64p.py
+++ b/b64p.py
@@ -59,7 +59,7 @@ def trimR(input, offset):
         if (offset == 0):
                 return input
         right_cut = offset_2_chars(offset)
-        return input[:-right_cut-1]
+        return input[:-right_cut]
 
 def encode(input):
         e1 = b64encode(input)