diff --git a/build-aux/cuirass/evaluate.scm b/build-aux/cuirass/evaluate.scm
index fc0744ad2a..0bd9e2481f 100644
--- a/build-aux/cuirass/evaluate.scm
+++ b/build-aux/cuirass/evaluate.scm
@@ -96,6 +96,7 @@
                                              (channels . ,channels))))))
                         (file
                          (string-append directory "/jobs-" system ".scm")))
+                    (close-inferior inferior)
                     (call-with-output-file file
                       (lambda (port)
                         (write jobs port)))))))