diff --git a/spacy/lang/lex_attrs.py b/spacy/lang/lex_attrs.py
index e6378a5a4..4c3284b1e 100644
--- a/spacy/lang/lex_attrs.py
+++ b/spacy/lang/lex_attrs.py
@@ -125,7 +125,7 @@ def word_shape(text):
 
 LEX_ATTRS = {
     attrs.LOWER: lambda string: string.lower(),
-    attrs.NORM: lambda string: string,
+    attrs.NORM: lambda string: string.lower(),
     attrs.PREFIX: lambda string: string[0],
     attrs.SUFFIX: lambda string: string[-3:],
     attrs.CLUSTER: lambda string: 0,