diff --git a/frappe/core/doctype/transaction_log/transaction_log.py b/frappe/core/doctype/transaction_log/transaction_log.py
index b5803aca4a..5110ae0931 100644
--- a/frappe/core/doctype/transaction_log/transaction_log.py
+++ b/frappe/core/doctype/transaction_log/transaction_log.py
@@ -29,12 +29,19 @@ class TransactionLog(Document):
 
 	def hash_line(self):
 		sha = hashlib.sha256()
-		sha.update(str(self.row_index) + str(self.timestamp) + str(self.data))
+		sha.update(
+			frappe.safe_encode(str(self.row_index)) + \
+			frappe.safe_encode(str(self.timestamp)) + \
+			frappe.safe_encode(str(self.data))
+		)
 		return sha.hexdigest()
 
 	def hash_chain(self):
 		sha = hashlib.sha256()
-		sha.update(str(self.transaction_hash) + str(self.previous_hash))
+		sha.update(
+			frappe.safe_encode(str(self.transaction_hash)) + \
+			frappe.safe_encode(str(self.previous_hash))
+		)
 		return sha.hexdigest()