diff --git a/frappe/core/doctype/doctype/doctype.json b/frappe/core/doctype/doctype/doctype.json
index 9aee40c2da..24a7a4c287 100644
--- a/frappe/core/doctype/doctype/doctype.json
+++ b/frappe/core/doctype/doctype/doctype.json
@@ -413,6 +413,7 @@
    "options": "InnoDB\nMyISAM"
   },
   {
+   "default": "0",
    "fieldname": "show_preview_popup",
    "fieldtype": "Check",
    "label": "Show Preview Popup"
@@ -420,7 +421,7 @@
  ],
  "icon": "fa fa-bolt",
  "idx": 6,
- "modified": "2019-05-16 09:18:29.373576",
+ "modified": "2019-05-16 14:58:33.405381",
  "modified_by": "Administrator",
  "module": "Core",
  "name": "DocType",
diff --git a/frappe/core/doctype/doctype/doctype.py b/frappe/core/doctype/doctype/doctype.py
index 5db025f9fb..7efdba3237 100644
--- a/frappe/core/doctype/doctype/doctype.py
+++ b/frappe/core/doctype/doctype/doctype.py
@@ -616,7 +616,9 @@ def validate_fields(meta):
 				frappe.throw(_("Options 'Dynamic Link' type of field must point to another Link Field with options as 'DocType'"))
 
 	def check_illegal_default(d):
-		if d.fieldtype == "Check" and d.default and d.default not in ('0', '1'):
+		if d.fieldtype == "Check" and not d.default:
+			d.default = '0'
+		if d.fieldtype == "Check" and d.default not in ('0', '1'):
 			frappe.throw(_("Default for 'Check' type of field must be either '0' or '1'"))
 		if d.fieldtype == "Select" and d.default and (d.default not in d.options.split("\n")):
 			frappe.throw(_("Default for {0} must be an option").format(d.fieldname))