diff --git a/lib/rake/application.rb b/lib/rake/application.rb
index 02586ad5e..d4e2680f6 100644
--- a/lib/rake/application.rb
+++ b/lib/rake/application.rb
@@ -124,7 +124,7 @@ def run_with_threads
 
       yield
 
-      thread_pool.join
+      thread_pool.join if defined?(@thread_pool)
       if options.job_stats
         stats = thread_pool.statistics
         puts "Maximum active threads: #{stats[:max_active_threads]} + main"