1 files changed, 10 insertions, 1 deletions

diff --git a/lisp/progmodes/sh-script.el b/lisp/progmodes/sh-script.el
index 508a9abaf4e..c30d2220269 100644
--- a/lisp/progmodes/sh-script.el
+++ b/lisp/progmodes/sh-script.el
@@ -128,7 +128,16 @@ shell it really is."
    ;; the executable extension, so comparisons with the list of
    ;; known shells work.
    (and (memq system-type '(ms-dos windows-nt))
-        (file-name-sans-extension (downcase (getenv "SHELL"))))
+        (let* ((shell (getenv "SHELL"))
+               (shell-base
+                (and shell (file-name-nondirectory shell))))
+          ;; shell-script mode doesn't support DOS/Windows shells,
+          ;; so use the default instead.
+          (if (or (null shell)
+                  (member (downcase shell-base)
+                          '("command.com" "cmd.exe" "4dos.com" "ndos.com")))
+              "/bin/sh"
+            (file-name-sans-extension (downcase shell)))))
    (getenv "SHELL")
    "/bin/sh")
   "*The executable file name for the shell being programmed."