diff --git a/erpnext/support/doctype/issue/test_issue.py b/erpnext/support/doctype/issue/test_issue.py
index 84f8c39..739324f 100644
--- a/erpnext/support/doctype/issue/test_issue.py
+++ b/erpnext/support/doctype/issue/test_issue.py
@@ -13,6 +13,10 @@
 class TestSetUp(unittest.TestCase):
 	def setUp(self):
 		frappe.db.sql("delete from `tabService Level Agreement`")
+		frappe.db.sql("delete from `tabService Level Priority`")
+		frappe.db.sql("delete from `tabSLA Fulfilled On Status`")
+		frappe.db.sql("delete from `tabPause SLA On Status`")
+		frappe.db.sql("delete from `tabService Day`")
 		frappe.db.set_value("Support Settings", None, "track_service_level_agreement", 1)
 		create_service_level_agreements_for_issues()
 
diff --git a/erpnext/support/doctype/service_level_agreement/service_level_agreement.py b/erpnext/support/doctype/service_level_agreement/service_level_agreement.py
index d9cffc2..472e96c 100644
--- a/erpnext/support/doctype/service_level_agreement/service_level_agreement.py
+++ b/erpnext/support/doctype/service_level_agreement/service_level_agreement.py
@@ -235,10 +235,9 @@
 		]
 
 	customer = doc.get('customer')
-	if customer:
-		or_filters.append(
-			["Service Level Agreement", "entity", "in", [customer, get_customer_group(customer), get_customer_territory(customer)]]
-		)
+	or_filters.append(
+		["Service Level Agreement", "entity", "in", [customer, get_customer_group(customer), get_customer_territory(customer)]]
+	)
 
 	default_sla_filter = filters + [["Service Level Agreement", "default_service_level_agreement", "=", 1]]
 	default_sla = frappe.get_all("Service Level Agreement", filters=default_sla_filter,