diff --git a/addons/payment/models/payment_transaction.py b/addons/payment/models/payment_transaction.py
index 97cd6732d54..24e231baf62 100644
--- a/addons/payment/models/payment_transaction.py
+++ b/addons/payment/models/payment_transaction.py
@@ -357,7 +357,7 @@ class PaymentTransaction(models.Model):
             # For instance, the prefix 'example' is a valid match for the existing references
             # 'example', 'example-1' and 'example-ref', in that order. Trusting the order to infer
             # the sequence number would lead to a collision with 'example-1'.
-            search_pattern = re.compile(rf'^{prefix}{separator}(\d+)$')
+            search_pattern = re.compile(rf'^{re.escape(prefix)}{separator}(\d+)$')
             max_sequence_number = 0  # If no match is found, start the sequence with this reference
             for existing_reference in same_prefix_references:
                 search_result = re.search(search_pattern, existing_reference)