diff --git a/lib/post_destroyer.rb b/lib/post_destroyer.rb
index d848ec75b79..7d5975747bb 100644
--- a/lib/post_destroyer.rb
+++ b/lib/post_destroyer.rb
@@ -330,6 +330,12 @@ class PostDestroyer
     allowed_user = @user.human? && @user.staff?
     return unless allowed_user && rs = reviewable.reviewable_scores.order('created_at DESC').first
 
+    # ReviewableScore#types is a superset of PostActionType#flag_types.
+    # If the reviewable score type is not on the latter, it means it's not a flag by a user and
+    #  must be an automated flag like `needs_approval`. There's no flag reason for these kind of types.
+    flag_type = PostActionType.flag_types[rs.reviewable_score_type]
+    return unless flag_type
+
     notify_responders = options[:notify_responders]
 
     Jobs.enqueue(
@@ -341,7 +347,7 @@ class PostDestroyer
         flagged_post_response_raw_content: @post.raw,
         url: notify_responders ? options[:parent_post].url : @post.url,
         flag_reason: I18n.t(
-          "flag_reasons#{".responder" if notify_responders}.#{PostActionType.types[rs.reviewable_score_type]}",
+          "flag_reasons#{".responder" if notify_responders}.#{flag_type}",
           locale: SiteSetting.default_locale,
           base_path: Discourse.base_path
         )
diff --git a/spec/models/reviewable_flagged_post_spec.rb b/spec/models/reviewable_flagged_post_spec.rb
index 8a7c81f2e66..003c5d0ea85 100644
--- a/spec/models/reviewable_flagged_post_spec.rb
+++ b/spec/models/reviewable_flagged_post_spec.rb
@@ -322,6 +322,14 @@ RSpec.describe ReviewableFlaggedPost, type: :model do
       expect(Jobs::SendSystemMessage.jobs.last["args"].first["message_type"]).to eq("flags_agreed_and_post_deleted_for_responders")
     end
 
+    it "skips responders notification when the score type doesn't match any post action flag type" do
+      flagged_post.reviewable_scores.first.update!(reviewable_score_type: ReviewableScore.types[:needs_approval])
+
+      expect {
+        flagged_post.perform(moderator, :delete_and_agree_replies)
+      }.not_to change(Jobs::SendSystemMessage.jobs, :size)
+    end
+
     it "ignores flagged responses" do
       SiteSetting.notify_users_after_responses_deleted_on_flagged_post = true
       flagged_reply = Fabricate(:reviewable_flagged_post, target: reply)
@@ -361,9 +369,9 @@ RSpec.describe ReviewableFlaggedPost, type: :model do
 
   def assert_pm_creation_enqueued(user_id, pm_type)
     expect(Jobs::SendSystemMessage.jobs.length).to eq(1)
-      job = Jobs::SendSystemMessage.jobs[0]
-      expect(job["args"][0]["user_id"]).to eq(user_id)
-      expect(job["args"][0]["message_type"]).to eq(pm_type)
+    job = Jobs::SendSystemMessage.jobs[0]
+    expect(job["args"][0]["user_id"]).to eq(user_id)
+    expect(job["args"][0]["message_type"]).to eq(pm_type)
   end
 
   def create_reply(post)