diff --git a/docs/source/index.rst b/docs/source/index.rst
index 4290f894b..54618b19a 100644
--- a/docs/source/index.rst
+++ b/docs/source/index.rst
@@ -208,7 +208,7 @@ problematic, given our starting assumptions:
     >>> from numpy.linalg import norm
     >>> import spacy.en
     >>> from spacy.parts_of_speech import ADV, VERB
-    >>> cosine = lambda v1, v2: dot(v1, v2) / (norm(v1), norm(v2))
+    >>> cosine = lambda v1, v2: dot(v1, v2) / (norm(v1) * norm(v2))
     >>> def is_bad_adverb(token, target_verb, tol):
     ...   if token.pos != ADV 
     ...     return False