diff --git a/mongoengine/fields.py b/mongoengine/fields.py
index 2e149330..a5dbf5d0 100644
--- a/mongoengine/fields.py
+++ b/mongoengine/fields.py
@@ -297,8 +297,9 @@ class DecimalField(BaseField):
         if value is None:
             return value
 
-        return decimal.Decimal(value).quantize(self.precision,
-                                               rounding=self.rounding)
+        # Convert to string for python 2.6 before casting to Decimal
+        value = decimal.Decimal("%s" % value)
+        return value.quantize(self.precision, rounding=self.rounding)
 
     def to_mongo(self, value):
         if value is None: