diff --git a/app/controllers/topics_controller.rb b/app/controllers/topics_controller.rb
index be5f02f41ac..67c844dbe61 100644
--- a/app/controllers/topics_controller.rb
+++ b/app/controllers/topics_controller.rb
@@ -687,11 +687,12 @@ class TopicsController < ApplicationController
 
   def invite_group
     group = Group.find_by(name: params[:group])
-    raise Discourse::NotFound unless group
+    raise Discourse::NotFound if !group
 
     topic = Topic.find_by(id: params[:topic_id])
+    raise Discourse::NotFound if !topic
 
-    unless pm_has_slots?(topic)
+    if !pm_has_slots?(topic)
       return render_json_error(
         I18n.t("pm_reached_recipients_limit", recipients_limit: SiteSetting.max_allowed_message_recipients)
       )
@@ -708,29 +709,29 @@ class TopicsController < ApplicationController
 
   def invite
     topic = Topic.find_by(id: params[:topic_id])
-    raise Discourse::InvalidParameters.new unless topic
+    raise Discourse::NotFound if !topic
 
-    username_or_email = params[:user] ? fetch_username : fetch_email
+    if !topic.private_message?
+      return render_json_error(I18n.t("topic_invite.not_pm"))
+    end
 
-    groups = Group.lookup_groups(
-      group_ids: params[:group_ids],
-      group_names: params[:group_names]
-    )
-
-    unless pm_has_slots?(topic)
+    if !pm_has_slots?(topic)
       return render_json_error(
         I18n.t("pm_reached_recipients_limit", recipients_limit: SiteSetting.max_allowed_message_recipients)
       )
     end
 
     guardian.ensure_can_invite_to!(topic)
-    group_ids = groups.map(&:id)
+
+    username_or_email = params[:user] ? fetch_username : fetch_email
+    group_ids = Group.lookup_groups(
+      group_ids: params[:group_ids],
+      group_names: params[:group_names]
+    ).pluck(:id)
 
     begin
       if topic.invite(current_user, username_or_email, group_ids, params[:custom_message])
-        user = User.find_by_username_or_email(username_or_email)
-
-        if user
+        if user = User.find_by_username_or_email(username_or_email)
           render_json_dump BasicUserSerializer.new(user, scope: guardian, root: 'user')
         else
           render json: success_json
diff --git a/app/models/topic.rb b/app/models/topic.rb
index 924b38f88cf..88578cdce4d 100644
--- a/app/models/topic.rb
+++ b/app/models/topic.rb
@@ -1029,11 +1029,9 @@ class Topic < ActiveRecord::Base
   end
 
   def invite(invited_by, username_or_email, group_ids = nil, custom_message = nil)
-    target_user = User.find_by_username_or_email(username_or_email)
     guardian = Guardian.new(invited_by)
-    is_email = username_or_email =~ /^.+@.+$/
 
-    if target_user
+    if target_user = User.find_by_username_or_email(username_or_email)
       if topic_allowed_users.exists?(user_id: target_user.id)
         raise UserExists.new(I18n.t("topic_invite.user_exists"))
       end
@@ -1064,7 +1062,7 @@ class Topic < ActiveRecord::Base
       else
         !!invite_to_topic(invited_by, target_user, group_ids, guardian)
       end
-    elsif is_email && guardian.can_invite_via_email?(self)
+    elsif username_or_email =~ /^.+@.+$/ && guardian.can_invite_via_email?(self)
       !!Invite.generate(invited_by,
         email: username_or_email,
         topic: self,
@@ -1781,6 +1779,13 @@ class Topic < ActiveRecord::Base
       SiteSetting.max_topic_invitations_per_day,
       1.day.to_i
     ).performed!
+
+    RateLimiter.new(
+      invited_by,
+      "topic-invitations-per-minute",
+      SiteSetting.max_topic_invitations_per_minute,
+      1.day.to_i
+    ).performed!
   end
 
   def cannot_permanently_delete_reason(user)
@@ -1853,8 +1858,9 @@ class Topic < ActiveRecord::Base
       ))
     end
 
+    rate_limit_topic_invitation(invited_by)
+
     Topic.transaction do
-      rate_limit_topic_invitation(invited_by)
       topic_allowed_users.create!(user_id: target_user.id) unless topic_allowed_users.exists?(user_id: target_user.id)
 
       user_in_allowed_group = (user.group_ids & topic_allowed_groups.map(&:group_id)).present?
diff --git a/config/locales/server.en.yml b/config/locales/server.en.yml
index 02a5f4e6935..eab63f07355 100644
--- a/config/locales/server.en.yml
+++ b/config/locales/server.en.yml
@@ -279,6 +279,7 @@ en:
 
   topic_invite:
     failed_to_invite: "The user cannot be invited into this topic without a group membership in either one of the following groups: %{group_names}."
+    not_pm: "You can only invite to private messages."
     user_exists: "Sorry, that user has already been invited. You may only invite a user to a topic once."
     muted_topic: "Sorry, that user muted this topic."
     receiver_does_not_allow_pm: "Sorry, that user does not allow you to send them private messages."
@@ -1791,6 +1792,7 @@ en:
     max_personal_messages_per_day: "Maximum number of new personal message topics a user can create per day."
     max_invites_per_day: "Maximum number of invites a user can send per day."
     max_topic_invitations_per_day: "Maximum number of topic invitations a user can send per day."
+    max_topic_invitations_per_minute: "Maximum number of topic invitations a user can send per minute."
 
     max_logins_per_ip_per_hour: "Maximum number of logins allowed per IP address per hour"
     max_logins_per_ip_per_minute: "Maximum number of logins allowed per IP address per minute"
diff --git a/config/site_settings.yml b/config/site_settings.yml
index 8243bd1a7bd..6ad7ebda537 100644
--- a/config/site_settings.yml
+++ b/config/site_settings.yml
@@ -1893,6 +1893,7 @@ rate_limits:
   max_edits_per_day: 30
   max_invites_per_day: 10
   max_topic_invitations_per_day: 30
+  max_topic_invitations_per_minute: 5
   max_topics_in_first_day: 3
   max_replies_in_first_day: 10
   tl2_additional_likes_per_day_multiplier: 1.5
diff --git a/spec/models/topic_spec.rb b/spec/models/topic_spec.rb
index 56abc419aed..3b569b901e6 100644
--- a/spec/models/topic_spec.rb
+++ b/spec/models/topic_spec.rb
@@ -723,7 +723,6 @@ RSpec.describe Topic do
 
     context 'with rate limits' do
       before do
-        SiteSetting.max_topic_invitations_per_day = 1
         RateLimiter.enable
         Group.refresh_automatic_groups!
       end
@@ -732,30 +731,68 @@ RSpec.describe Topic do
         RateLimiter.clear_all!
       end
 
-      it "rate limits topic invitations" do
-        start = Time.now.tomorrow.beginning_of_day
-        freeze_time(start)
+      context 'when per day' do
+        before do
+          SiteSetting.max_topic_invitations_per_day = 1
+        end
 
-        topic = Fabricate(:topic, user: trust_level_2)
+        it "rate limits topic invitations" do
+          start = Time.now.tomorrow.beginning_of_day
+          freeze_time(start)
 
-        topic.invite(topic.user, user.username)
+          topic = Fabricate(:topic, user: trust_level_2)
 
-        expect {
-          topic.invite(topic.user, user1.username)
-        }.to raise_error(RateLimiter::LimitExceeded)
+          topic.invite(topic.user, user.username)
+
+          expect {
+            topic.invite(topic.user, user1.username)
+          }.to raise_error(RateLimiter::LimitExceeded)
+        end
+
+        it "rate limits PM invitations" do
+          start = Time.now.tomorrow.beginning_of_day
+          freeze_time(start)
+
+          topic = Fabricate(:private_message_topic, user: trust_level_2)
+
+          topic.invite(topic.user, user.username)
+
+          expect {
+            topic.invite(topic.user, user1.username)
+          }.to raise_error(RateLimiter::LimitExceeded)
+        end
       end
 
-      it "rate limits PM invitations" do
-        start = Time.now.tomorrow.beginning_of_day
-        freeze_time(start)
+      context 'when per minute' do
+        before do
+          SiteSetting.max_topic_invitations_per_minute = 1
+        end
 
-        topic = Fabricate(:private_message_topic, user: trust_level_2)
+        it "rate limits topic invitations" do
+          start = Time.now.tomorrow.beginning_of_minute
+          freeze_time(start)
 
-        topic.invite(topic.user, user.username)
+          topic = Fabricate(:topic, user: trust_level_2)
 
-        expect {
-          topic.invite(topic.user, user1.username)
-        }.to raise_error(RateLimiter::LimitExceeded)
+          topic.invite(topic.user, user.username)
+
+          expect {
+            topic.invite(topic.user, user1.username)
+          }.to raise_error(RateLimiter::LimitExceeded)
+        end
+
+        it "rate limits PM invitations" do
+          start = Time.now.tomorrow.beginning_of_minute
+          freeze_time(start)
+
+          topic = Fabricate(:private_message_topic, user: trust_level_2)
+
+          topic.invite(topic.user, user.username)
+
+          expect {
+            topic.invite(topic.user, user1.username)
+          }.to raise_error(RateLimiter::LimitExceeded)
+        end
       end
     end
 
diff --git a/spec/requests/api/topics_spec.rb b/spec/requests/api/topics_spec.rb
index 79dcf58525c..ac690323c3f 100644
--- a/spec/requests/api/topics_spec.rb
+++ b/spec/requests/api/topics_spec.rb
@@ -229,7 +229,7 @@ RSpec.describe 'topics' do
 
         let(:username) { Fabricate(:user).username }
         let(:request_body) { { user: username } }
-        let(:id) { Fabricate(:topic).id }
+        let(:id) { Fabricate(:private_message_topic).id }
 
         run_test! do |response|
           data = JSON.parse(response.body)
diff --git a/spec/requests/topics_controller_spec.rb b/spec/requests/topics_controller_spec.rb
index 212c55466d2..fe79743a80b 100644
--- a/spec/requests/topics_controller_spec.rb
+++ b/spec/requests/topics_controller_spec.rb
@@ -4047,77 +4047,17 @@ RSpec.describe TopicsController do
         sign_in(user)
       end
 
-      context 'as a valid user' do
+      context 'when topic id is not PM' do
         fab!(:user_topic) { Fabricate(:topic, user: user) }
 
         it 'should return the right response' do
           user.update!(trust_level: SiteSetting.min_trust_level_to_allow_invite)
 
-          expect do
-            post "/t/#{user_topic.id}/invite.json", params: {
-              email: 'someguy@email.com'
-            }
-          end.to change { Invite.where(invited_by_id: user.id).count }.by(1)
-
-          expect(response.status).to eq(200)
-          expect(Jobs::InviteEmail.jobs.first['args'].first['invite_to_topic']).to be_truthy
-        end
-      end
-
-      context 'when user is a group manager' do
-        fab!(:group) { Fabricate(:group).tap { |g| g.add_owner(user) } }
-        fab!(:private_category)  { Fabricate(:private_category, group: group) }
-
-        fab!(:group_private_topic) do
-          Fabricate(:topic, category: private_category, user: user)
-        end
-
-        let!(:recipient) { 'jake@adventuretime.ooo' }
-
-        before_all do
-          user.update!(trust_level: SiteSetting.min_trust_level_to_allow_invite)
-        end
-
-        it "should attach group to the invite" do
-          post "/t/#{group_private_topic.id}/invite.json", params: {
-            user: recipient,
-            group_ids: "#{group.id},9999999"
+          post "/t/#{user_topic.id}/invite.json", params: {
+            email: 'someguy@email.com'
           }
 
-          expect(response.status).to eq(200)
-          expect(Invite.find_by(email: recipient).groups).to contain_exactly(group)
-        end
-
-        context 'when group is available to automatic groups only' do
-          before do
-            group.update!(automatic: true)
-          end
-
-          it 'should return the right response' do
-            post "/t/#{group_private_topic.id}/invite.json", params: {
-              user: user
-            }
-
-            expect(response.status).to eq(403)
-          end
-        end
-
-        context 'when user is not part of the required group' do
-          it 'should return the right response' do
-            post "/t/#{group_private_topic.id}/invite.json", params: {
-              user: user
-            }
-
-            expect(response.status).to eq(422)
-
-            response_body = response.parsed_body
-
-            expect(response_body["errors"]).to eq([
-              I18n.t("topic_invite.failed_to_invite",
-                group_names: group.name
-              )
-            ])
-          end
+          expect(response.status).to eq(422)
         end
       end
 
@@ -4129,13 +4069,13 @@ RSpec.describe TopicsController do
             email: user.email
           }
 
-          expect(response.status).to eq(400)
+          expect(response.status).to eq(404)
         end
       end
 
       it 'requires an email parameter' do
         post "/t/#{topic.id}/invite.json"
-        expect(response.status).to eq(400)
+        expect(response.status).to eq(422)
       end
 
       context "when PM has reached maximum allowed numbers of recipients" do
@@ -4180,28 +4120,6 @@ RSpec.describe TopicsController do
         end
       end
     end
-
-    context "when inviting a group to a topic" do
-      fab!(:group) { Fabricate(:group) }
-
-      before do
-        sign_in(admin)
-      end
-
-      it "should work correctly" do
-        email = 'hiro@from.heros'
-
-        post "/t/#{topic.id}/invite.json", params: {
-          email: email, group_ids: group.id
-        }
-
-        expect(response.status).to eq(200)
-
-        groups = Invite.find_by(email: email).groups
-        expect(groups.count).to eq(1)
-        expect(groups.first.id).to eq(group.id)
-      end
-    end
   end
 
   describe 'invite_group' do