diff --git a/lib/tasks/assets.rake b/lib/tasks/assets.rake
index 9263f015206..85debe82334 100644
--- a/lib/tasks/assets.rake
+++ b/lib/tasks/assets.rake
@@ -176,10 +176,9 @@ def compress(from, to)
 end
 
 def concurrent?
-  executor = Concurrent::FixedThreadPool.new(Concurrent.processor_count)
-
   if ENV["SPROCKETS_CONCURRENT"] == "1"
     concurrent_compressors = []
+    executor = Concurrent::FixedThreadPool.new(Concurrent.processor_count)
     yield(Proc.new { |&block| concurrent_compressors << Concurrent::Future.execute(executor: executor) { block.call } })
     concurrent_compressors.each(&:wait!)
   else