diff --git a/gnu/packages/python-science.scm b/gnu/packages/python-science.scm
index 36894f000a..6b0b70a1b8 100644
--- a/gnu/packages/python-science.scm
+++ b/gnu/packages/python-science.scm
@@ -3144,7 +3144,13 @@ (define-public python-traittypes
     (arguments
      (list
       ;; This one test fails because it doesn't raise an expected exception.
-      #:test-flags #~(list "-k" "not test_bad_values")))
+      #:test-flags '(list "-k" "not test_bad_values")
+      #:phases
+      '(modify-phases %standard-phases
+         (add-after 'unpack 'numpy-compatibility
+           (lambda _
+             (substitute* "traittypes/tests/test_traittypes.py"
+               (("np\\.int") "int")))))))
     (propagated-inputs (list python-traitlets))
     (native-inputs
      (list python-numpy