diff --git a/gnu/packages/python-xyz.scm b/gnu/packages/python-xyz.scm
index fb6e49bcec..4fa4f153a7 100644
--- a/gnu/packages/python-xyz.scm
+++ b/gnu/packages/python-xyz.scm
@@ -2902,9 +2902,6 @@ somewhat intelligible.")
      '(#:phases (modify-phases %standard-phases
                   (replace 'check
                     (lambda _
-                      (setenv "PYTHONPATH"
-                              (string-append "./build/lib:"
-                                             (getenv "PYTHONPATH")))
                       (invoke "pytest" "-vv"))))))
     (native-inputs
      `(("python-pytest" ,python-pytest)))