diff --git a/lisp/erc/erc-common.el b/lisp/erc/erc-common.el
index 116f702ab3e..1a0b9c323d1 100644
--- a/lisp/erc/erc-common.el
+++ b/lisp/erc/erc-common.el
@@ -641,25 +641,6 @@ Otherwise, return LIST-OR-ATOM."
          (car ,list-or-atom)
        ,list-or-atom))))
 
-(defmacro erc--doarray (spec &rest body)
-  "Map over ARRAY, running BODY with VAR bound to iteration element.
-Behave more or less like `seq-doseq', but tailor operations for
-arrays.
-
-\(fn (VAR ARRAY [RESULT]) BODY...)"
-  (declare (indent 1) (debug ((symbolp form &optional form) body)))
-  (let ((array (make-symbol "array"))
-        (len (make-symbol "len"))
-        (i (make-symbol "i")))
-    `(let* ((,array ,(nth 1 spec))
-            (,len (length ,array))
-            (,i 0))
-       (while-let (((< ,i ,len))
-                   (,(car spec) (aref ,array ,i)))
-         ,@body
-         (cl-incf ,i))
-       ,(nth 2 spec))))
-
 (provide 'erc-common)
 
 ;;; erc-common.el ends here
diff --git a/lisp/erc/erc.el b/lisp/erc/erc.el
index cec261feb43..572b73188e3 100644
--- a/lisp/erc/erc.el
+++ b/lisp/erc/erc.el
@@ -7607,7 +7607,7 @@ Use the getter of the same name to retrieve the current value.")
           (ct (make-char-table 'erc--channel-mode-types))
           (type ?a))
       (dolist (cs types)
-        (erc--doarray (c cs)
+        (seq-doseq (c cs)
           (aset ct c type))
         (cl-incf type))
       (make-erc--channel-mode-types :key key
@@ -7626,7 +7626,7 @@ complement relevant letters in STRING."
          (table (erc--channel-mode-types-table obj))
          (fallbackp (erc--channel-mode-types-fallbackp obj))
          (+p t))
-    (erc--doarray (c string)
+    (seq-doseq (c string)
       (cond ((= ?+ c) (setq +p t))
             ((= ?- c) (setq +p nil))
             ((and status-letters (string-search (string c) status-letters))
@@ -7719,7 +7719,7 @@ dropped were they not already absent."
   (let ((addp t)
         ;;
         redundant-add redundant-drop adding dropping)
-    (erc--doarray (c string)
+    (seq-doseq (c string)
       (pcase c
         (?+ (setq addp t))
         (?- (setq addp nil))
diff --git a/test/lisp/erc/erc-tests.el b/test/lisp/erc/erc-tests.el
index 1bbee0dad52..5c1a34bc3fa 100644
--- a/test/lisp/erc/erc-tests.el
+++ b/test/lisp/erc/erc-tests.el
@@ -165,19 +165,6 @@
 
     (advice-remove 'buffer-local-value 'erc-with-server-buffer)))
 
-(ert-deftest erc--doarray ()
-  (let ((array "abcdefg")
-        out)
-    ;; No return form.
-    (should-not (erc--doarray (c array) (push c out)))
-    (should (equal out '(?g ?f ?e ?d ?c ?b ?a)))
-
-    ;; Return form evaluated upon completion.
-    (setq out nil)
-    (should (= 42 (erc--doarray (c array (+ 39 (length out)))
-                    (when (cl-evenp c) (push c out)))))
-    (should (equal out '(?f ?d ?b)))))
-
 (ert-deftest erc-hide-prompt ()
   (let ((erc-hide-prompt erc-hide-prompt)
         (inhibit-message noninteractive)