diff --git a/app/services/search_indexer.rb b/app/services/search_indexer.rb
index 40104c5b13c..530ac26c6d0 100644
--- a/app/services/search_indexer.rb
+++ b/app/services/search_indexer.rb
@@ -87,7 +87,17 @@ class SearchIndexer
           .scan(TS_VECTOR_PARSE_REGEX)
           .map do |term, _, indexes|
             new_indexes =
-              indexes.split(",").map { |index| additional_words[index.to_i - 1][1] }.join(",")
+              indexes
+                .split(",")
+                .map do |index|
+                  existing_positions = additional_words[index.to_i - 1]
+                  if existing_positions
+                    existing_positions[1]
+                  else
+                    index
+                  end
+                end
+                .join(",")
             "#{term}#{new_indexes}"
           end
           .join(" ")
diff --git a/spec/services/search_indexer_spec.rb b/spec/services/search_indexer_spec.rb
index 13890c884c0..b8c1cc8b9eb 100644
--- a/spec/services/search_indexer_spec.rb
+++ b/spec/services/search_indexer_spec.rb
@@ -139,6 +139,24 @@ RSpec.describe SearchIndexer do
       }
     end
 
+    it "should work with edge case domain names" do
+      # 00E5A4 stems to 00e5 and a4, which is odd, but by-design
+      # this may cause internal indexing to fail due to indexes not aligning
+      # when stuffing terms for domains
+      post.update!(cooked: <<~HTML)
+        Test.00E5A4.1
+      HTML
+
+      SearchIndexer.update_posts_index(
+        post_id: post.id,
+        topic_title: post.topic.title,
+        category_name: post.topic.category&.name,
+        topic_tags: post.topic.tags.map(&:name).join(" "),
+        cooked: post.cooked,
+        private_message: post.topic.private_message?,
+      )
+    end
+
     it "should work with invalid HTML" do
       post.update!(cooked: "<FD>" * Nokogiri::Gumbo::DEFAULT_MAX_TREE_DEPTH)