diff --git a/lib/brakeman/processors/lib/rails2_route_processor.rb b/lib/brakeman/processors/lib/rails2_route_processor.rb
index f72d4de7980b5a020d43b264a91e73a69c8982ad..88402b84799dd55e7545869754ae643e8d7bf2b5 100644
--- a/lib/brakeman/processors/lib/rails2_route_processor.rb
+++ b/lib/brakeman/processors/lib/rails2_route_processor.rb
@@ -229,7 +229,9 @@ class Brakeman::Rails2RoutesProcessor < Brakeman::BaseProcessor
 
     @prefix << camelize(call.first_arg.value)
 
-    @nested = Sexp.new(:lvar, formal_args.lhs)
+    if formal_args
+      @nested = Sexp.new(:lvar, formal_args.lhs)
+    end
 
     process block