diff --git a/app/controllers/csv_preview_controller.rb b/app/controllers/csv_preview_controller.rb
index aac85218ca..074d0a3193 100644
--- a/app/controllers/csv_preview_controller.rb
+++ b/app/controllers/csv_preview_controller.rb
@@ -16,10 +16,10 @@ def show
 
     parent_document_path = URI(@asset["parent_document_url"]).request_uri
     @content_item = GdsApi.content_store.content_item(parent_document_path).to_hash
-
     @attachment_metadata = @content_item.dig("details", "attachments").select do |attachment|
-      attachment["url"] =~ /#{Regexp.escape(asset_path)}$/
+      attachment["filename"] == asset_filename
     end
+
     original_error = nil
     row_sep = :auto
     download_file = params[:legacy] ? whitehall_media_download : media_download
@@ -58,6 +58,10 @@ def asset_path
     request.path.sub("/preview", "").sub(/^\//, "")
   end
 
+  def asset_filename
+    asset_path.split("/").last
+  end
+
   def whitehall_media_download
     GdsApi.asset_manager.whitehall_media(asset_path).body
   end
diff --git a/test/integration/csv_preview_test.rb b/test/integration/csv_preview_test.rb
index e95d1c06a9..db983d2713 100644
--- a/test/integration/csv_preview_test.rb
+++ b/test/integration/csv_preview_test.rb
@@ -243,6 +243,7 @@ def setup_asset_manager(legacy_url_path, parent_document_url, asset_manager_id =
   end
 
   def setup_content_item_legacy(legacy_url_path, parent_document_base_path)
+    filename = legacy_url_path.split("/").last
     content_item = {
       base_path: parent_document_base_path,
       document_type: "guidance",
@@ -251,11 +252,13 @@ def setup_content_item_legacy(legacy_url_path, parent_document_base_path)
         attachments: [
           {
             title: "Attachment 1",
-            url: "https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/5678/filename.csv",
+            filename: "file.csv",
+            url: "https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/5678/file.csv",
             file_size: "1024",
           },
           {
             title: "Attachment 2",
+            filename:,
             url: "https://www.gov.uk/#{legacy_url_path}",
             file_size: "2048",
           },
@@ -280,6 +283,7 @@ def setup_content_item_legacy(legacy_url_path, parent_document_base_path)
   end
 
   def setup_content_item_non_legacy(non_legacy_url_path, parent_document_base_path)
+    filename = non_legacy_url_path.split("/").last
     content_item = {
       base_path: parent_document_base_path,
       document_type: "guidance",
@@ -288,11 +292,13 @@ def setup_content_item_non_legacy(non_legacy_url_path, parent_document_base_path
         attachments: [
           {
             title: "Attachment 1",
-            url: "https://www.gov.uk/media/5678/filename.csv",
+            filename: "file.csv",
+            url: "https://www.gov.uk/media/5678/file.csv",
             file_size: "1024",
           },
           {
             title: "Attachment 2",
+            filename:,
             url: "https://www.gov.uk/#{non_legacy_url_path}",
             file_size: "2048",
           },