diff --git a/docs/userguide b/docs/userguide
index 3d935e40..d6dbde00 100644
--- a/docs/userguide
+++ b/docs/userguide
@@ -1857,9 +1857,13 @@ window, you cannot simply bind it to a key.  +i3-input+ is a tool created
 for this purpose: It lets you input a command and sends the command to i3. It
 can also prefix this command and display a custom prompt for the input dialog.
 
+The additional +--toggle+ option will remove the mark if the window already has
+this mark, add it if the window has none or replace the current mark if it has
+another mark.
+
 *Syntax*:
 ------------------------------
-mark identifier
+mark [--toggle] identifier
 [con_mark="identifier"] focus
 unmark identifier
 ------------------------------
diff --git a/include/commands.h b/include/commands.h
index 780a9e8e..0f7e3635 100644
--- a/include/commands.h
+++ b/include/commands.h
@@ -109,10 +109,10 @@ void cmd_workspace_back_and_forth(I3_CMD);
 void cmd_workspace_name(I3_CMD, char *name);
 
 /**
- * Implementation of 'mark <mark>'
+ * Implementation of 'mark [--toggle] <mark>'
  *
  */
-void cmd_mark(I3_CMD, char *mark);
+void cmd_mark(I3_CMD, char *mark, char *toggle);
 
 /**
  * Implementation of 'unmark [mark]'
diff --git a/parser-specs/commands.spec b/parser-specs/commands.spec
index 315a9218..87db6cf0 100644
--- a/parser-specs/commands.spec
+++ b/parser-specs/commands.spec
@@ -189,10 +189,12 @@ state FLOATING:
   floating = 'enable', 'disable', 'toggle'
       -> call cmd_floating($floating)
 
-# mark <mark>
+# mark [--toggle] <mark>
 state MARK:
+  toggle = '--toggle'
+      ->
   mark = string
-      -> call cmd_mark($mark)
+      -> call cmd_mark($mark, $toggle)
 
 # unmark [mark]
 state UNMARK:
diff --git a/src/commands.c b/src/commands.c
index 9b51b3ec..ea0b9032 100644
--- a/src/commands.c
+++ b/src/commands.c
@@ -1037,26 +1037,41 @@ void cmd_workspace_name(I3_CMD, char *name) {
 }
 
 /*
- * Implementation of 'mark <mark>'
+ * Implementation of 'mark [--toggle] <mark>'
  *
  */
-void cmd_mark(I3_CMD, char *mark) {
-    DLOG("Clearing all windows which have that mark first\n");
-
-    Con *con;
-    TAILQ_FOREACH(con, &all_cons, all_cons) {
-        if (con->mark && strcmp(con->mark, mark) == 0)
-            FREE(con->mark);
-    }
-
-    DLOG("marking window with str %s\n", mark);
-    owindow *current;
-
+void cmd_mark(I3_CMD, char *mark, char *toggle) {
     HANDLE_EMPTY_MATCH;
 
+    owindow *current;
     TAILQ_FOREACH(current, &owindows, owindows) {
         DLOG("matching: %p / %s\n", current->con, current->con->name);
-        current->con->mark = sstrdup(mark);
+        if (toggle != NULL && current->con->mark && strcmp(current->con->mark, mark) == 0) {
+            DLOG("removing window mark %s\n", mark);
+            FREE(current->con->mark);
+        } else {
+            DLOG("marking window with str %s\n", mark);
+            FREE(current->con->mark);
+            current->con->mark = sstrdup(mark);
+        }
+    }
+
+    DLOG("Clearing all non-matched windows with this mark\n");
+    Con *con;
+    TAILQ_FOREACH(con, &all_cons, all_cons) {
+        /* Skip matched windows, we took care of them already. */
+        bool matched = false;
+        TAILQ_FOREACH(current, &owindows, owindows) {
+            if (current->con == con) {
+                matched = true;
+                break;
+            }
+        }
+        if (matched)
+            continue;
+
+        if (con->mark && strcmp(con->mark, mark) == 0)
+            FREE(con->mark);
     }
 
     cmd_output->needs_tree_render = true;
diff --git a/testcases/t/210-mark-unmark.t b/testcases/t/210-mark-unmark.t
index f285338b..0083547f 100644
--- a/testcases/t/210-mark-unmark.t
+++ b/testcases/t/210-mark-unmark.t
@@ -16,11 +16,19 @@
 #
 # checks if mark and unmark work correctly
 use i3test;
+use List::Util qw(first);
 
 sub get_marks {
     return i3(get_socket_path())->get_marks->recv;
 }
 
+sub get_mark_for_window_on_workspace {
+    my ($ws, $con) = @_;
+
+    my $current = first { $_->{window} == $con->{id} } @{get_ws_content($ws)};
+    return $current->{mark};
+}
+
 ##############################################################
 # 1: check that there are no marks set yet
 ##############################################################
@@ -76,4 +84,61 @@ cmd 'unmark';
 
 is_deeply(get_marks(), [], 'all marks removed');
 
+##############################################################
+# 4: mark a con, use same mark to mark another con,
+#    check that only the latter is marked
+##############################################################
+
+my $first = open_window;
+my $second = open_window;
+
+cmd 'mark important';
+cmd 'focus left';
+cmd 'mark important';
+
+is(get_mark_for_window_on_workspace($tmp, $first), 'important', 'first container now has the mark');
+ok(!get_mark_for_window_on_workspace($tmp, $second), 'second container lost the mark');
+
+##############################################################
+# 5: mark a con, toggle the mark, check that the mark is gone
+##############################################################
+
+my $con = open_window;
+cmd 'mark important';
+cmd 'mark --toggle important';
+ok(!get_mark_for_window_on_workspace($tmp, $con), 'container no longer has the mark');
+
+##############################################################
+# 6: toggle a mark on an unmarked con, check it is marked
+##############################################################
+
+my $con = open_window;
+cmd 'mark --toggle important';
+is(get_mark_for_window_on_workspace($tmp, $con), 'important', 'container now has the mark');
+
+##############################################################
+# 7: mark a con, toggle a different mark, check it is marked
+#    with the new mark
+##############################################################
+
+my $con = open_window;
+cmd 'mark boring';
+cmd 'mark --toggle important';
+is(get_mark_for_window_on_workspace($tmp, $con), 'important', 'container has the most recent mark');
+
+##############################################################
+# 8: mark a con, toggle the mark on another con,
+#    check only the latter has the mark
+##############################################################
+
+my $first = open_window;
+my $second = open_window;
+
+cmd 'mark important';
+cmd 'focus left';
+cmd 'mark --toggle important';
+
+is(get_mark_for_window_on_workspace($tmp, $first), 'important', 'left container has the mark now');
+ok(!get_mark_for_window_on_workspace($tmp, $second), 'second containr no longer has the mark');
+
 done_testing;