diff --git a/app/controllers/concerns/issue_templates_common.rb b/app/controllers/concerns/issue_templates_common.rb
index 2b50b1d6..1d963556 100644
--- a/app/controllers/concerns/issue_templates_common.rb
+++ b/app/controllers/concerns/issue_templates_common.rb
@@ -109,7 +109,7 @@ def core_fields_map_by_tracker_id(tracker_id: nil, project_id: nil)
 
       if field == 'watcher_user_ids' && project_id.present?
         issue = Issue.new(tracker_id: tracker_id, project_id: project_id)
-        watchers = helpers.users_for_new_issue_watchers(issue)
+        watchers = users_for_new_issue_watchers_with_limit(issue, nil)
         value[:field_format] = 'list'
 
         value[:possible_values] = watchers.map { |user| "#{user.name} :#{user.id}" }
@@ -149,4 +149,16 @@ def custom_fields_map_by_tracker_id(tracker_id = nil)
     logger&.info "core_fields_map_by_tracker_id failed due to this error: #{e.message}"
     {}
   end
+
+  # https://github.com/redmine/redmine/blob/master/app/helpers/issues_helper.rb
+  # Returns an array of users that are proposed as watchers
+  # on the new issue form
+  def users_for_new_issue_watchers_with_limit(issue, limit = 21)
+    users = issue.watcher_users.select{|u| u.status == User::STATUS_ACTIVE}
+    assignable_watchers = issue.project.principals.assignable_watchers.limit(limit)
+    if limit.nil? || assignable_watchers.size < limit
+      users += assignable_watchers.sort
+    end
+    users.uniq
+  end
 end
diff --git a/assets/javascripts/issue_templates.js b/assets/javascripts/issue_templates.js
index 983cce9d..e12afb56 100644
--- a/assets/javascripts/issue_templates.js
+++ b/assets/javascripts/issue_templates.js
@@ -423,12 +423,49 @@ ISSUE_TEMPLATE.prototype = {
     document.getElementById('issue_template').dispatchEvent(changeEvent)
   },
   checkSelectedWatchers: function (values) {
-    let targets = document.querySelectorAll('input[name="issue[watcher_user_ids][]"]')
-    for (let i = 0; i < targets.length; i++) {
-      let target = targets[i]
-      if (values.includes(target.value)) {
-        target.checked = true
+    let targets = document.querySelectorAll('input[type="checkbox"][name="issue[watcher_user_ids][]"]')
+    if (targets.length > 0) {
+      for (let i = 0; i < targets.length; i++) {
+        let target = targets[i]
+        if (values.includes(target.value)) {
+          target.checked = true
+        }
       }
+    } else {
+      let observer = new MutationObserver((mutations) => {
+        mutations.forEach((mutation) => {
+          if (!mutation.addedNodes) return
+
+          for (let i = 0; i < mutation.addedNodes.length; i++) {
+            let node = mutation.addedNodes[i]
+            console.log(node)
+            if (node.id === 'new-watcher-form') {
+              observer.disconnect()
+
+              // Check watchers from template setting
+              let searchTargets = document.querySelectorAll('div#users_for_watcher input[name="watcher[user_ids][]"]')
+              for (let i = 0; i < searchTargets.length; i++) {
+                let target = searchTargets[i]
+                if (values.includes(target.value)) {
+                  target.checked = true
+                }
+              }
+              // Click "Add" button to apply checked watchers and close the dialog
+              document.querySelector('form#new-watcher-form input[type="submit"]').click()
+            }
+          }
+        })
+      })
+
+      observer.observe(document.body, {
+        childList: true,
+        subtree: true,
+        attributes: false,
+        characterData: false
+      })
+
+      // Click "Search for watchers to add" link to open "Add watchers" dialog
+      document.querySelector('span.search_for_watchers a').click()
     }
   },
   filterTemplate: function (event) {