diff --git a/src/emacs/server.lisp b/src/emacs/server.lisp
index ce4ded56..1643ffd5 100644
--- a/src/emacs/server.lisp
+++ b/src/emacs/server.lisp
@@ -66,8 +66,11 @@ return a value json-serialize accepts: a plist, vector, string, number, t,
                                    :timeout timeout)))
            (handler-case
                (progn
+                 ;; Like emacsclient, end every argument with a space; newer
+                 ;; servers reject a request line that does not end in one.
                  (write-string "-eval " stream)
                  (write-string (emacs-server-quote form) stream)
+                 (write-char #\Space stream)
                  (write-char #\Newline stream)
                  (finish-output stream)
                  (emacs-server--read-reply stream))
diff --git a/tests/emacs-tests.lisp b/tests/emacs-tests.lisp
index ee8e1540..6294460c 100644
--- a/tests/emacs-tests.lisp
+++ b/tests/emacs-tests.lisp
@@ -137,8 +137,8 @@
                         (format stream "-emacs-pid 42~%-print \"abc~%-print-nonl &_def\"~%")))
                 (test-assert (equal (emacs-server-evaluate socket "(foo bar)") "\"abc def\"")
                              "Print chunks join and unquote.")))
-             (test-assert (equal request "-eval (foo&_bar)")
-                          "The request is one quoted -eval line.")
+             (test-assert (equal request "-eval (foo&_bar) ")
+                          "The request is one quoted -eval line ending in a space.")
              (join-thread
               (prog1 (emacs-test-serve-once
                       socket