diff --git a/gnu/packages/python-xyz.scm b/gnu/packages/python-xyz.scm
index 5a3c6b670e..e011d37e91 100644
--- a/gnu/packages/python-xyz.scm
+++ b/gnu/packages/python-xyz.scm
@@ -15484,7 +15484,8 @@ reasoning, wrappers for natural language processing libraries.")
        (method url-fetch)
        (uri (pypi-uri "nltk" version ".zip"))
        (sha256
-        (base32 "153x2clrnigs74jdgnn3qmljdjj4gprmvpdvh49i18ls4m8mbm5y"))))))
+        (base32 "153x2clrnigs74jdgnn3qmljdjj4gprmvpdvh49i18ls4m8mbm5y"))))
+    (propagated-inputs `(("python-six" ,python-six)))))
 
 (define-public python2-nltk
   (package-with-python2 python-nltk))