diff --git a/spacy/vocab.pyx b/spacy/vocab.pyx
index 9af55790a..bbfe17599 100644
--- a/spacy/vocab.pyx
+++ b/spacy/vocab.pyx
@@ -404,7 +404,7 @@ cdef class Vocab:
             norm = 0.0
             for i in range(vec_len):
                 norm += lexeme.vector[i] * lexeme.vector[i]
-            lex.l2_norm = sqrt(norm)
+            lexeme.l2_norm = sqrt(norm)
         self.vectors_length = vec_len
         return vec_len