diff --git a/erpnext/support/doctype/issue/issue.py b/erpnext/support/doctype/issue/issue.py
index d5e5b78288..e211e24c40 100644
--- a/erpnext/support/doctype/issue/issue.py
+++ b/erpnext/support/doctype/issue/issue.py
@@ -236,7 +236,7 @@ def is_first_response(issue):
 	return False
 
 def calculate_first_response_time(issue, first_responded_on):
-	issue_creation_date = issue.creation
+	issue_creation_date = issue.service_level_agreement_creation or issue.creation
 	issue_creation_time = get_time_in_seconds(issue_creation_date)
 	first_responded_on_in_seconds = get_time_in_seconds(first_responded_on)
 	support_hours = frappe.get_cached_doc("Service Level Agreement", issue.service_level_agreement).support_and_resolution