diff --git a/app/controllers/pdfviewer_controller.rb b/app/controllers/pdfviewer_controller.rb
index 8df99abd..5a24595b 100644
--- a/app/controllers/pdfviewer_controller.rb
+++ b/app/controllers/pdfviewer_controller.rb
@@ -1,7 +1,11 @@
 class PdfviewerController < ApplicationController
   layout "pdfviewer"
   def index
-    @id = params[:id]
-    @parent_id = FileSet.find(@id).parent_id
+    if FileSet.exists?(params[:id])
+      @id = params[:id]
+      @parent_id = FileSet.find(@id).parent_id
+    else
+      redirect_to root_path, alert: "Document not found"
+    end
   end
 end
\ No newline at end of file