diff --git a/chartmogul/__init__.py b/chartmogul/__init__.py
index f245fbe..7674c7a 100644
--- a/chartmogul/__init__.py
+++ b/chartmogul/__init__.py
@@ -30,7 +30,7 @@
 """
 
 __title__ = 'chartmogul'
-__version__ = '1.4.1'
+__version__ = '1.5.0'
 __build__ = 0x000000
 __author__ = 'ChartMogul Ltd'
 __license__ = 'MIT'
diff --git a/chartmogul/api/activity.py b/chartmogul/api/activity.py
index 5d5e167..cf72eda 100644
--- a/chartmogul/api/activity.py
+++ b/chartmogul/api/activity.py
@@ -13,17 +13,17 @@ class Activity(Resource):
 
     class _Schema(Schema):
         id = fields.Int()
-        activity_arr = fields.Number(load_from='activity-arr')
-        activity_mrr = fields.Number(load_from='activity-mrr')
-        activity_mrr_movement = fields.Number(load_from='activity-mrr-movement')
+        activity_arr = fields.Number(data_key='activity-arr')
+        activity_mrr = fields.Number(data_key='activity-mrr')
+        activity_mrr_movement = fields.Number(data_key='activity-mrr-movement')
         currency = fields.String()
-        currency_sign = fields.String(load_from='currency-sign')
+        currency_sign = fields.String(data_key='currency-sign')
         date = fields.DateTime()
         description = fields.String()
         type = fields.String()
 
         @post_load
-        def make(self, data):
+        def make(self, data, **kwargs):
             return Activity(**data)
 
-    _schema = _Schema(strict=True)
+    _schema = _Schema()
diff --git a/chartmogul/api/attributes.py b/chartmogul/api/attributes.py
index 64768ff..22df1bf 100644
--- a/chartmogul/api/attributes.py
+++ b/chartmogul/api/attributes.py
@@ -14,7 +14,7 @@ class _Schema(Schema):
         custom = fields.Dict()
 
         @post_load
-        def make(self, data):
+        def make(self, data, **kwargs):
             return Attributes(**data)
 
-    _schema = _Schema(strict=True)
+    _schema = _Schema()
diff --git a/chartmogul/api/custom_attrs.py b/chartmogul/api/custom_attrs.py
index 17aa9ad..04aea88 100644
--- a/chartmogul/api/custom_attrs.py
+++ b/chartmogul/api/custom_attrs.py
@@ -14,11 +14,11 @@ class _Schema(Schema):
         custom = fields.Dict()
 
         @post_load
-        def make(self, data):
+        def make(self, data, **kwargs):
             return CustomAttributes(**data)
 
     _customers = namedtuple('Customers', ['entries'])
-    _schema = _Schema(strict=True)
+    _schema = _Schema()
 
     @classmethod
     def _load(cls, response):
@@ -31,7 +31,7 @@ def _load(cls, response):
             return None
         jsonObj = response.json()
         if 'entries' in jsonObj:
-            customers = Customer._schema.load(jsonObj['entries'], many=True).data
+            customers = Customer._schema.load(jsonObj['entries'], many=True)
             return cls._customers(customers)
         else:
-            return cls._schema.load(jsonObj).data
+            return cls._schema.load(jsonObj)
diff --git a/chartmogul/api/customer.py b/chartmogul/api/customer.py
index 38a1084..b641aca 100644
--- a/chartmogul/api/customer.py
+++ b/chartmogul/api/customer.py
@@ -20,7 +20,7 @@ class _Schema(Schema):
         state = fields.String(allow_none=True)
 
         @post_load
-        def make(self, data):
+        def make(self, data, **kwargs):
             return Address(**data)
 
 
@@ -56,21 +56,21 @@ class _Schema(Schema):
         external_ids = fields.List(fields.String())
         data_source_uuids = fields.List(fields.String())
         status = fields.String()
-        customer_since = fields.DateTime(load_from="customer-since", allow_none=True)
+        customer_since = fields.DateTime(data_key="customer-since", allow_none=True)
         mrr = fields.Number()
         arr = fields.Number()
-        billing_system_url = fields.String(load_from="billing-system-url", allow_none=True)
-        chartmogul_url = fields.String(load_from="chartmogul-url")
-        billing_system_type = fields.String(load_from="billing-system-type")
+        billing_system_url = fields.String(data_key="billing-system-url", allow_none=True)
+        chartmogul_url = fields.String(data_key="chartmogul-url")
+        billing_system_type = fields.String(data_key="billing-system-type")
         currency = fields.String()
-        currency_sign = fields.String(load_from="currency-sign")
+        currency_sign = fields.String(data_key="currency-sign")
         address = fields.Nested(Address._Schema, allow_none=True)
 
         @post_load
-        def make(self, data):
+        def make(self, data, **kwargs):
             return Customer(**data)
 
-    _schema = _Schema(strict=True)
+    _schema = _Schema()
 
 
 Customer.search = Customer._method('all', 'get', '/customers/search')
diff --git a/chartmogul/api/data_source.py b/chartmogul/api/data_source.py
index c20a570..6e43d61 100644
--- a/chartmogul/api/data_source.py
+++ b/chartmogul/api/data_source.py
@@ -19,7 +19,7 @@ class _Schema(Schema):
         system = fields.Str()
 
         @post_load
-        def make(self, data):
+        def make(self, data, **kwargs):
             return DataSource(**data)
 
-    _schema = _Schema(strict=True)
+    _schema = _Schema()
diff --git a/chartmogul/api/invoice.py b/chartmogul/api/invoice.py
index be613ab..4f1a773 100644
--- a/chartmogul/api/invoice.py
+++ b/chartmogul/api/invoice.py
@@ -24,9 +24,10 @@ class _Schema(Schema):
         tax_amount_in_cents = fields.Int()
         transaction_fees_in_cents = fields.Int()
         account_code = fields.String(allow_none=True)
+        description = fields.String(allow_none=True)
 
         @post_load
-        def make(self, data):
+        def make(self, data, **kwargs):
             return LineItem(**data)
 
 
@@ -54,10 +55,10 @@ class _Schema(Schema):
         transactions = fields.Nested(Transaction._Schema, many=True)
 
         @post_load
-        def make(self, data):
+        def make(self, data, **kwargs):
             return Invoice(**data)
 
-    _schema = _Schema(strict=True)
+    _schema = _Schema()
 
     @classmethod
     def all(cls, config, **kwargs):
diff --git a/chartmogul/api/metrics.py b/chartmogul/api/metrics.py
index c063428..93df5dd 100644
--- a/chartmogul/api/metrics.py
+++ b/chartmogul/api/metrics.py
@@ -10,13 +10,13 @@ class Summary(DataObject):
     class _Schema(Schema):
         current = fields.Number()
         previous = fields.Number()
-        percentage_change = fields.Number(load_from='percentage-change')
+        percentage_change = fields.Number(data_key='percentage-change')
 
         @post_load
-        def make(self, data):
+        def make(self, data, **kwargs):
             return Summary(**data)
 
-    _schema = _Schema(strict=True)
+    _schema = _Schema()
 
 
 class Metrics(Resource):
@@ -33,8 +33,8 @@ class _Schema(Schema):
         Fields are optional, so a subset present is good enough
         """
         date = fields.Date()
-        customer_churn_rate = fields.Number(load_from='customer-churn-rate')
-        mrr_churn_rate = fields.Number(load_from='mrr-churn-rate')
+        customer_churn_rate = fields.Number(data_key='customer-churn-rate')
+        mrr_churn_rate = fields.Number(data_key='mrr-churn-rate')
         ltv = fields.Number()
         customers = fields.Number()
         asp = fields.Number()
@@ -42,22 +42,22 @@ class _Schema(Schema):
         arr = fields.Number()
         mrr = fields.Number()
         # MRR only
-        mrr_new_business = fields.Number(load_from='mrr-new-business')
-        mrr_expansion = fields.Number(load_from='mrr-expansion')
-        mrr_contraction = fields.Number(load_from='mrr-contraction')
-        mrr_churn = fields.Number(load_from='mrr-churn')
-        mrr_reactivation = fields.Number(load_from='mrr-reactivation')
+        mrr_new_business = fields.Number(data_key='mrr-new-business')
+        mrr_expansion = fields.Number(data_key='mrr-expansion')
+        mrr_contraction = fields.Number(data_key='mrr-contraction')
+        mrr_churn = fields.Number(data_key='mrr-churn')
+        mrr_reactivation = fields.Number(data_key='mrr-reactivation')
 
         @post_load
-        def make(self, data):
+        def make(self, data, **kwargs):
             return Metrics(**data)
 
-    _schema = _Schema(strict=True)
+    _schema = _Schema()
 
     @classmethod
     def _many(cls, entries, **kwargs):
         if 'summary' in kwargs:
-            kwargs['summary'] = Summary._schema.load(kwargs['summary']).data
+            kwargs['summary'] = Summary._schema.load(kwargs['summary'])
         return cls._many_cls(entries, **kwargs)
 
 
diff --git a/chartmogul/api/ping.py b/chartmogul/api/ping.py
index ceeebbd..44d2e26 100644
--- a/chartmogul/api/ping.py
+++ b/chartmogul/api/ping.py
@@ -13,10 +13,10 @@ class _Schema(Schema):
         data = fields.String()
 
         @post_load
-        def make(self, data):
+        def make(self, data, **kwargs):
             return Ping(**data)
 
-    _schema = _Schema(strict=True)
+    _schema = _Schema()
 
 
 _add_method(Ping, "ping", "get")
diff --git a/chartmogul/api/plan.py b/chartmogul/api/plan.py
index 104ba57..3b34a15 100644
--- a/chartmogul/api/plan.py
+++ b/chartmogul/api/plan.py
@@ -20,7 +20,7 @@ class _Schema(Schema):
         external_id = fields.String()
 
         @post_load
-        def make(self, data):
+        def make(self, data, **kwargs):
             return Plan(**data)
 
-    _schema = _Schema(strict=True)
+    _schema = _Schema()
diff --git a/chartmogul/api/plan_group.py b/chartmogul/api/plan_group.py
index 86acf53..9d3b764 100644
--- a/chartmogul/api/plan_group.py
+++ b/chartmogul/api/plan_group.py
@@ -18,10 +18,10 @@ class _Schema(Schema):
         plans_count = fields.Int()
 
         @post_load
-        def make(self, data):
+        def make(self, data, **kwargs):
             return PlanGroup(**data)
 
-    _schema = _Schema(strict=True)
+    _schema = _Schema()
 
     @classmethod
     def all(cls, config, **kwargs):
diff --git a/chartmogul/api/plan_group_plans.py b/chartmogul/api/plan_group_plans.py
index 039cb84..51dee44 100644
--- a/chartmogul/api/plan_group_plans.py
+++ b/chartmogul/api/plan_group_plans.py
@@ -20,7 +20,7 @@ class _Schema(Schema):
         external_id = fields.String()
 
         @post_load
-        def make(self, data):
+        def make(self, data, **kwargs):
             return PlanGroupPlans(**data)
 
-    _schema = _Schema(strict=True)
+    _schema = _Schema()
diff --git a/chartmogul/api/subscription.py b/chartmogul/api/subscription.py
index 1cff52e..aa4a9c2 100644
--- a/chartmogul/api/subscription.py
+++ b/chartmogul/api/subscription.py
@@ -19,12 +19,12 @@ class _Schema(Schema):
         mrr = fields.Number(allow_none=True)
         arr = fields.Number(allow_none=True)
         status = fields.String(allow_none=True)
-        billing_cycle = fields.String(load_from='billing-cycle', allow_none=True)
-        billing_cycle_count = fields.Number(load_from='billing-cycle-count', allow_none=True)
-        start_date = fields.DateTime(load_from='start-date', allow_none=True)
-        end_date = fields.DateTime(load_from='end-date', allow_none=True)
+        billing_cycle = fields.String(data_key='billing-cycle', allow_none=True)
+        billing_cycle_count = fields.Number(data_key='billing-cycle-count', allow_none=True)
+        start_date = fields.DateTime(data_key='start-date', allow_none=True)
+        end_date = fields.DateTime(data_key='end-date', allow_none=True)
         currency = fields.String(allow_none=True)
-        currency_sign = fields.String(load_from='currency-sign', allow_none=True)
+        currency_sign = fields.String(data_key='currency-sign', allow_none=True)
 
         # /import namespace
         uuid = fields.String(allow_none=True)
@@ -36,17 +36,17 @@ class _Schema(Schema):
         cancellation_dates = fields.List(fields.DateTime(), allow_none=True)
 
         @post_load
-        def make(self, data):
+        def make(self, data, **kwargs):
             return Subscription(**data)
 
-    _schema = _Schema(strict=True)
+    _schema = _Schema()
 
     # /import has different paging
     @classmethod
     def _loadJSON(cls, jsonObj):
         if "subscriptions" in jsonObj:
             _many = namedtuple('Subscriptions', ["subscriptions", "current_page", "total_pages", "customer_uuid"])
-            return _many(cls._schema.load(jsonObj["subscriptions"], many=True).data,
+            return _many(cls._schema.load(jsonObj["subscriptions"], many=True),
                          jsonObj["current_page"],
                          jsonObj["total_pages"],
                          jsonObj["customer_uuid"])
diff --git a/chartmogul/api/tags.py b/chartmogul/api/tags.py
index 7c1acf0..cefbf06 100644
--- a/chartmogul/api/tags.py
+++ b/chartmogul/api/tags.py
@@ -14,11 +14,11 @@ class _Schema(Schema):
         tags = fields.List(fields.String())
 
         @post_load
-        def make(self, data):
+        def make(self, data, **kwargs):
             return Tags(**data)
 
     _customers = namedtuple('Customers', ['entries'])
-    _schema = _Schema(strict=True)
+    _schema = _Schema()
 
     @classmethod
     def _load(cls, response):
@@ -31,7 +31,7 @@ def _load(cls, response):
             return None
         jsonObj = response.json()
         if 'entries' in jsonObj:
-            customers = Customer._schema.load(jsonObj['entries'], many=True).data
+            customers = Customer._schema.load(jsonObj['entries'], many=True)
             return cls._customers(customers)
         else:
-            return cls._schema.load(jsonObj).data
+            return cls._schema.load(jsonObj)
diff --git a/chartmogul/api/transaction.py b/chartmogul/api/transaction.py
index 37b3501..0aac759 100644
--- a/chartmogul/api/transaction.py
+++ b/chartmogul/api/transaction.py
@@ -17,7 +17,7 @@ class _Schema(Schema):
         result = fields.String()
 
         @post_load
-        def make(self, data):
+        def make(self, data, **kwargs):
             return Transaction(**data)
 
-    _schema = _Schema(strict=True)
+    _schema = _Schema()
diff --git a/chartmogul/resource.py b/chartmogul/resource.py
index 6373289..ba695fa 100644
--- a/chartmogul/resource.py
+++ b/chartmogul/resource.py
@@ -1,12 +1,14 @@
-import requests
+from builtins import str
+from datetime import date, datetime
 from json import dumps
+
+import requests
 from promise import Promise
 from uritemplate import URITemplate
-from .retry_request import requests_retry_session
-from .errors import APIError, ConfigurationError, ArgumentMissingError, annotateHTTPError
+
 from .api.config import Config
-from datetime import datetime, date
-from builtins import str
+from .errors import APIError, ArgumentMissingError, ConfigurationError, annotateHTTPError
+from .retry_request import requests_retry_session
 
 """
 HTTP verb mapping. Based on nodejs library.
@@ -96,10 +98,10 @@ def _load(cls, response):
     def _loadJSON(cls, jsonObj):
         # has load_many capability & is many entries result?
         if '_root_key' in dir(cls) is not None and cls._root_key in jsonObj:
-            return cls._many(cls._schema.load(jsonObj[cls._root_key], many=True).data,
+            return cls._many(cls._schema.load(jsonObj[cls._root_key], many=True),
                              **{key: jsonObj[key] for key in LIST_PARAMS if key in jsonObj})
         else:
-            return cls._schema.load(jsonObj).data
+            return cls._schema.load(jsonObj)
 
     @classmethod
     def _preProcessParams(cls, params):
diff --git a/requirements.txt b/requirements.txt
index bc0f400..dc55eb2 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,5 +1,5 @@
 requests>=2.10.0
 uritemplate>=3.0.0
 promise>=1.0.1
-marshmallow>=2.12.1,<3
+marshmallow>=3.10.0
 future>=0.16.0
diff --git a/setup.py b/setup.py
index 29c668f..853f797 100644
--- a/setup.py
+++ b/setup.py
@@ -17,7 +17,7 @@
     'requests>=2.10.0',
     'uritemplate>=3.0.0',
     'promise>=1.0.1',
-    'marshmallow>=2.12.1,<3',
+    'marshmallow>=3.10.0',
     'future>=0.16.0',
 ]
 test_requirements = [