diff --git a/lisp/simple.el b/lisp/simple.el
index 3ac6b86381..20e22bf98f 100644
--- a/lisp/simple.el
+++ b/lisp/simple.el
@@ -3549,13 +3549,11 @@ shell-command
                   (if async-shell-command-display-buffer
                       (display-buffer buffer '(nil (allow-no-window . t)))
                     (add-function :before (process-filter proc)
                                   (lambda (process _string)
                                     (let ((buf (process-buffer process)))
-                                      (when (and (zerop (buffer-size buf))
-                                                 (string= (buffer-name buf)
-                                                          bname))
+                                      (when (string= (buffer-name buf) bname)
                                         (display-buffer buf))))))))
 	    ;; Otherwise, command is executed synchronously.
 	    (shell-command-on-region (point) (point) command
 				     output-buffer nil error-buffer)))))))