diff --git a/app/controllers/mpa_controller.rb b/app/controllers/mpa_controller.rb
index a84dfbf..dd6295e 100644
--- a/app/controllers/mpa_controller.rb
+++ b/app/controllers/mpa_controller.rb
@@ -69,7 +69,7 @@ def pept2data
     end
 
     @response.each do |entry|
-      entry["lineage"] = @lineages[entry["lca"]]
+      entry["lineage"] = @lineages[entry["lca"].to_s]
     end
 
     @response