diff --git a/boto3/dynamodb/types.py b/boto3/dynamodb/types.py
index f358b12f55..4e6c9796bb 100644
--- a/boto3/dynamodb/types.py
+++ b/boto3/dynamodb/types.py
@@ -286,7 +286,7 @@ def _deserialize_bool(self, value):
         return value
 
     def _deserialize_n(self, value):
-        return DYNAMODB_CONTEXT.create_decimal(value)
+        return DYNAMODB_CONTEXT.create_decimal(Decimal(value).normalize())
 
     def _deserialize_s(self, value):
         return value
diff --git a/tests/unit/dynamodb/test_types.py b/tests/unit/dynamodb/test_types.py
index 0a6c2a07f3..96d30966e0 100644
--- a/tests/unit/dynamodb/test_types.py
+++ b/tests/unit/dynamodb/test_types.py
@@ -167,6 +167,10 @@ def test_deserialize_integer(self):
 
     def test_deserialize_decimal(self):
         assert self.deserializer.deserialize({'N': '1.25'}) == Decimal('1.25')
+        assert self.deserializer.deserialize({'N': '1.2500'}) == Decimal('1.25')
+        assert self.deserializer.deserialize({'N': '1234567891234560000000000000000000000000'}) == Decimal('1.23456789123456E+39')
+        assert self.deserializer.deserialize({'N': '-1234567891234560000000000000000000000000'}) == Decimal('-1.23456789123456E+39')
+        assert self.deserializer.deserialize({'N': '1.23E+39'}) == Decimal('1.23E+39')
 
     def test_deserialize_string(self):
         assert self.deserializer.deserialize({'S': 'foo'}) == 'foo'