diff --git a/extensions/vi-mode/options.lisp b/extensions/vi-mode/options.lisp
index 7d2e22e91..a055e9157 100644
--- a/extensions/vi-mode/options.lisp
+++ b/extensions/vi-mode/options.lisp
@@ -317,9 +317,7 @@
   (:set-hook (new-value)
    (setf (lem:variable-value 'lem/line-numbers:line-numbers :global) new-value)))
 
-(defvar *default-iskeyword* '("@" "48-57" "_" "192-255"))
-
-(defun compile-iskeyword (value)
+(defun compile-rules (value option-name)
   (apply #'disjoin
          (mapcar (lambda (rule)
                    (check-type rule string)
@@ -343,13 +341,18 @@
                           (progn
                             (unless (= (length rule) 1)
                               (error 'option-error
-                                     :format-control "Invalid rule in iskeyword: ~A"
-                                     :format-arguments (list rule)))
+                                     :format-control "Invalid rule in ~A: ~A"
+                                     :format-arguments (list option-name rule)))
                             (let ((rule-char (aref rule 0)))
                               (lambda (c)
                                 (char= c rule-char))))))))
                  value)))
 
+(defvar *default-iskeyword* '("@" "48-57" "_" "192-255"))
+
+(defun compile-iskeyword (value)
+  (compile-rules value "iskeyword"))
+
 (define-option "iskeyword" ((cons *default-iskeyword*
                                      (compile-iskeyword *default-iskeyword*))
                             :type list
@@ -376,6 +379,37 @@
                    (option-value option))
             :test 'equal)))))
 
+(defvar *default-isseparator* (mapcar #'string '(#\Newline #\Space #\Tab)))
+
+(defun compile-isseparator (value)
+  (compile-rules value "isseparator"))
+
+(define-option "isseparator" 
+  ((cons *default-isseparator*
+         (compile-isseparator *default-isseparator*))
+   :type list
+   :aliases ("iss")
+   :scope :buffer)
+  (:documentation "Comma-separated string to specify the characters that should be recognized as non broad word characters. (buffer local)
+  Aliases: iss")
+  (:getter (option)
+   (car (option-raw-value option)))
+  (:setter (new-value option)
+   (setf (option-%value option)
+         (cons new-value
+               (compile-isseparator new-value))))
+  (:initializer (option)
+   (let ((syntax-table (lem:mode-syntax-table (lem:buffer-major-mode (lem:current-buffer)))))
+     (setf (option-value option)
+           (delete-duplicates
+            (nconc (mapcar (lambda (c)
+                             (if (char= c #\@)
+                                 "@-@"
+                                 (string c)))
+                           (lem-base::syntax-table-space-chars syntax-table))
+                   (option-value option))
+            :test 'equal)))))
+
 (define-option "scrolloff" (0 :type number :aliases ("so"))
   (:documentation "The minimal number of lines to keep above of below the cursor.
 Default: 0
diff --git a/extensions/vi-mode/tests/options.lisp b/extensions/vi-mode/tests/options.lisp
index d4c0f5fa1..473868c9c 100644
--- a/extensions/vi-mode/tests/options.lisp
+++ b/extensions/vi-mode/tests/options.lisp
@@ -7,9 +7,13 @@
   (:import-from :lem-fake-interface
                 :with-fake-interface)
   (:shadowing-import-from :lem-vi-mode/tests/utils
-                          :with-current-buffer))
+                          :with-current-buffer)
+  (:import-from :named-readtables
+                :in-readtable))
 (in-package :lem-vi-mode/tests/options)
 
+(in-readtable :interpol-syntax)
+
 (deftest get-option
   (ok (typep (get-option "number") 'option)
       "Can get a global option")
@@ -24,3 +28,18 @@
         (with-current-buffer (buf)
           (ok (equalp (option-value "iskeyword") isk)
               "Another buffer's local option is not changed"))))))
+
+(deftest isseparator-option
+  (ok (typep (get-option "isseparator") 'option)
+      "Can get isseparator option")
+  (ok (typep (get-option "iss") 'option)
+      "Can get isseparator option by alias")
+  (with-fake-interface ()
+    (with-vi-buffer (#?"abc\n[(]def)\n")
+      (cmd "E")
+      (ok (buf= #?"abc\n(def[)]\n")))
+    (with-vi-buffer (#?"abc\n[(]def)\n")
+      (execute-set-command "iss+=(")
+      (execute-set-command "iss+=)")
+      (cmd "WE")
+      (ok (buf= #?"abc\n(de[f])\n")))))
\ No newline at end of file
diff --git a/extensions/vi-mode/word.lisp b/extensions/vi-mode/word.lisp
index 2353514f8..3f00867a1 100644
--- a/extensions/vi-mode/word.lisp
+++ b/extensions/vi-mode/word.lisp
@@ -30,10 +30,15 @@
       ((blank-char-p char) :blank)
       (t :non-word))))
 
+(defun non-broad-word-char-p (char)
+  (funcall (cdr (option-raw-value "isseparator"))
+           char))
+
 (defun broad-word-char-type (char)
   (when char
     (cond
       ((blank-char-p char) :blank)
+      ((non-broad-word-char-p char) :non-word)
       (t :word))))
 
 (defun forward-word-begin (char-type-fn &optional (point (current-point)))