diff --git a/gash/gash.scm b/gash/gash.scm
index 28f6da1..594ef61 100644
--- a/gash/gash.scm
+++ b/gash/gash.scm
@@ -140,7 +140,13 @@ There is NO WARRANTY, to the extent permitted by law.
                  (write-history HOME)
                  (newline)))
               (else (exit (run-repl (current-input-port) parse?))))))))
-    (thunk)))
+    ;; Mes exits abnormally if an exception is not caught.
+    (cond-expand
+     (mes (catch 'shell-error
+            thunk
+            (lambda args
+              (exit 1))))
+     (else (thunk)))))
 
 (cond-expand
  (mes (define (prompt) "$ "))