diff --git a/minirake b/minirake
index 09592980f..00675ba39 100755
--- a/minirake
+++ b/minirake
@@ -562,7 +562,7 @@ class RakeApp
   end
 
   def wait_process
-    sleep 0.1
+    Thread.pass
 
     exited = []
     $rake_fiber_table.each do |pid, v|