diff --git a/app/helpers/comments_helper.rb b/app/helpers/comments_helper.rb
index 377e50c6e3d..9a4266dc4b6 100644
--- a/app/helpers/comments_helper.rb
+++ b/app/helpers/comments_helper.rb
@@ -302,7 +302,7 @@ def cancel_delete_comment_link(comment)
   # return html link to mark/unmark comment as spam
   def tag_comment_as_spam_link(comment)
     if comment.approved
-      link_to(ts("Spam"), reject_comment_path(comment), method: :put, confirm: "Are you sure you want to mark this as spam?" )
+      link_to(ts("Spam"), reject_comment_path(comment), method: :put, data: { confirm: "Are you sure you want to mark this as spam?" })
     else
       link_to(ts("Not Spam"), approve_comment_path(comment), method: :put)
     end
diff --git a/features/comments_and_kudos/spam_comments.feature b/features/comments_and_kudos/spam_comments.feature
index 7a959d3b12a..ef87225955a 100644
--- a/features/comments_and_kudos/spam_comments.feature
+++ b/features/comments_and_kudos/spam_comments.feature
@@ -46,3 +46,31 @@ Feature: Marking comments as spam
 
     When I follow "Default Admin Post"
     Then I should see "Comments (1)"
+
+  Scenario: Author can mark comments as spam
+    Given I am logged in as "author"
+      And I post the work "Popular Fic"
+      And I log out
+    When I view the work "Popular Fic" with comments
+      And I post a spam comment
+      And I post a guest comment
+      And I am logged in as "author"
+      And I view the work "Popular Fic" with comments
+    Then I should see "Comments (2)"
+      And I should see "Buy my product"
+    When I mark the comment as spam
+    Then I should see "Comments (1)"
+      And I should not see "Buy my product"
+
+  @javascript
+  Scenario: If Javascript is enabled, there's a confirmation popup before marking a comment as spam
+    Given the work "Popular Fic" by "author"
+      And a guest comment on the work "Popular Fic"
+      And a guest comment on the work "Popular Fic"
+    When I am logged in as "author"
+      And I view the work "Popular Fic" with comments
+    Then I should see "Comments (2)"
+    When I mark the comment as spam
+      And I confirm I want to mark the comment as spam
+      And I view the work "Popular Fic" with comments
+    Then I should see "Comments (1)"
diff --git a/features/step_definitions/comment_steps.rb b/features/step_definitions/comment_steps.rb
index c434b7ea7c3..9167278d888 100644
--- a/features/step_definitions/comment_steps.rb
+++ b/features/step_definitions/comment_steps.rb
@@ -302,3 +302,11 @@
     click_link("Yes, delete!") # TODO: Fix along with comment deletion.
   end
 end
+
+When "I mark the comment as spam" do
+  click_link("Spam")
+end
+
+When "I confirm I want to mark the comment as spam" do
+  expect(page.accept_alert).to eq("Are you sure you want to mark this as spam?") if @javascript
+end