diff --git a/gnu/packages/python-xyz.scm b/gnu/packages/python-xyz.scm
index 115ccef217..daaa521568 100644
--- a/gnu/packages/python-xyz.scm
+++ b/gnu/packages/python-xyz.scm
@@ -26314,12 +26314,12 @@ source bytes using the UTF-8 encoding and then rewrites Python 3.6 style
        (file-name (git-file-name name version))))
     (build-system python-build-system)
     (arguments
-     `(#:phases
-       (modify-phases %standard-phases
-         (replace 'check
-           (lambda* (#:key tests? #:allow-other-keys)
-             (when tests?
-               (invoke "pytest" "-vv")))))))
+     (list #:phases
+           #~(modify-phases %standard-phases
+               (replace 'check
+                 (lambda* (#:key tests? #:allow-other-keys)
+                   (when tests?
+                     (invoke "pytest" "-vv")))))))
     (native-inputs (list python-pytest))
     (home-page "https://github.com/python/typed_ast")
     (synopsis "Fork of Python @code{ast} modules with type comment support")