diff --git a/lisp/erc/erc-common.el b/lisp/erc/erc-common.el
index 28ab6aad466..e7e70fffd3a 100644
--- a/lisp/erc/erc-common.el
+++ b/lisp/erc/erc-common.el
@@ -52,7 +52,7 @@
   string insertp sendp)
 
 (cl-defstruct (erc--input-split (:include erc-input
-                                          (string :read-only)
+                                          (string "" :read-only t)
                                           (insertp erc-insert-this)
                                           (sendp (with-suppressed-warnings
                                                      ((obsolete erc-send-this))
diff --git a/test/lisp/erc/erc-tests.el b/test/lisp/erc/erc-tests.el
index 2318fed28f2..b3912cab33d 100644
--- a/test/lisp/erc/erc-tests.el
+++ b/test/lisp/erc/erc-tests.el
@@ -849,7 +849,7 @@
   ;; truncation ellipsis when run interactively.  Rather than have
   ;; hard-to-read "nondeterministic" comparisons against sets of
   ;; acceptable values, we use separate tests.
-  (when (display-graphic-p) (ert-pass))
+  (when (char-displayable-p ?…) (ert-pass))
 
   ;; Truncation cache populated and used.
   (let ((cache (erc--channel-mode-types-shortargs erc--channel-mode-types))
@@ -877,7 +877,7 @@
 (ert-deftest erc--channel-modes/graphic-p ()
   :tags `(:unstable ,@(and (getenv "ERC_TESTS_GRAPHICAL")
                            '(:erc--graphical)))
-  (unless (display-graphic-p) (ert-skip "See non-/graphic-p variant"))
+  (unless (char-displayable-p ?…) (ert-skip "See non-/graphic-p variant"))
 
   (erc-tests-common-init-server-proc "sleep" "1")
   (setq erc--isupport-params (make-hash-table)