diff --git a/ietf/ipr/forms.py b/ietf/ipr/forms.py
index 96b31b772..d5d2c00a7 100644
--- a/ietf/ipr/forms.py
+++ b/ietf/ipr/forms.py
@@ -107,7 +107,7 @@ class DraftForm(forms.ModelForm):
         help_texts = { 'sections': 'Sections' }
 
 validate_patent_number = RegexValidator(
-                                    regex="^(([A-Z][A-Z]\d\d/\d{6}|[A-Z][A-Z]\d{6,12}([A-Z]\d?)?|[A-Z][A-Z]\d{4}(\w{1,2}\d{5,7})?)[, ]*)+$",
+                                    regex="^(([A-Z][A-Z]\d\d/\d{6}|[A-Z][A-Z]\d{6,12}([A-Z]\d?)?|[A-Z][A-Z]\d{4}(\w{1,2}\d{5,7})?|[A-Z][A-Z]\d{15})[, ]*)+$",
                                     message="Please enter one or more patent publication or application numbers as country code and serial number, e.g.: US62/123456 or WO2017123456." )
 
 def validate_string(s, letter_min, digit_min, space_min, message):