diff --git a/spacy/errors.py b/spacy/errors.py
index f171b0037..161b5cad6 100644
--- a/spacy/errors.py
+++ b/spacy/errors.py
@@ -943,6 +943,7 @@ class Errors(metaclass=ErrorsWithCodes):
              "{value}.")
     E1044 = ("Special characters definition for '{label}' may not contain upper-case chars where case_sensitive==False.")
     E1045 = ("Invalid affix group config '{label}'.")
+    E1046 = ("Special characters definition may not contain characters that occupy four bytes in UTF-16.")
 
 
 # Deprecated model shortcuts, only used in errors and warnings