diff --git a/modoboa/core/password_hashers/base.py b/modoboa/core/password_hashers/base.py
index f264fd2d2..156a35616 100644
--- a/modoboa/core/password_hashers/base.py
+++ b/modoboa/core/password_hashers/base.py
@@ -55,7 +55,7 @@ class PasswordHasher(object):
         :return: True if passwords match, False otherwise
         """
         return constant_time_compare(
-            self._encrypt(clearvalue, hashed_value),
+            self._b64encode(self._encrypt(clearvalue, hashed_value)),
             hashed_value
         )