diff --git a/spacy/errors.py b/spacy/errors.py
index 5ee1476c2..f55b378e9 100644
--- a/spacy/errors.py
+++ b/spacy/errors.py
@@ -707,7 +707,7 @@ class Errors(metaclass=ErrorsWithCodes):
             "need to modify the pipeline, use the built-in methods like "
             "`nlp.add_pipe`, `nlp.remove_pipe`, `nlp.disable_pipe` or "
             "`nlp.enable_pipe` instead.")
-    E927 = ("Can't write to frozen list Maybe you're trying to modify a computed "
+    E927 = ("Can't write to frozen list. Maybe you're trying to modify a computed "
             "property or default function argument?")
     E928 = ("A KnowledgeBase can only be serialized to/from from a directory, "
             "but the provided argument {loc} points to a file.")