diff --git a/frappe/model/base_document.py b/frappe/model/base_document.py
index dbd03a8574..785c6ed07e 100644
--- a/frappe/model/base_document.py
+++ b/frappe/model/base_document.py
@@ -231,10 +231,11 @@ class BaseDocument(object):
 
 	def _fix_numeric_types(self):
 		for df in self.meta.get("fields"):
-			if df.fieldtype in ("Int", "Check"):
-				self.set(df.fieldname, cint(self.get(df.fieldname)))
-			elif df.fieldtype in ("Float", "Currency"):
-				self.set(df.fieldname, flt(self.get(df.fieldname)))
+			if self.get(df.fieldname) is not None:
+				if df.fieldtype in ("Int", "Check"):
+					self.set(df.fieldname, cint(self.get(df.fieldname)))
+				elif df.fieldtype in ("Float", "Currency"):
+					self.set(df.fieldname, flt(self.get(df.fieldname)))
 
 		if self.docstatus is not None:
 			self.docstatus = cint(self.docstatus)
diff --git a/frappe/model/db_query.py b/frappe/model/db_query.py
index 68d3411629..5ee6b71eea 100644
--- a/frappe/model/db_query.py
+++ b/frappe/model/db_query.py
@@ -24,7 +24,7 @@ class DatabaseQuery(object):
 		limit_page_length=20, as_list=False, with_childnames=False, debug=False,
 		ignore_permissions=False, user=None):
 		if not ignore_permissions and not frappe.has_permission(self.doctype, "read", user=user):
-			raise frappe.PermissionError
+			raise frappe.PermissionError, self.doctype
 
 		if fields:
 			self.fields = fields