diff --git a/trytond/model/modelstorage.py b/trytond/model/modelstorage.py
index 93e40b1ba8..33b93c4aba 100644
--- a/trytond/model/modelstorage.py
+++ b/trytond/model/modelstorage.py
@@ -1093,7 +1093,7 @@ class ModelStorage(Model):
                             or any(d is None for d in digits)):
                         return
                     if isinstance(value, Decimal):
-                        exp = Decimal(str(10.0 ** -digits[1]).rstrip('0'))
+                        exp = Decimal('.'.join(['0', '0' * digits[1]]))
                         if value.quantize(exp) != value:
                             raise_user_error(value)
                     else: