diff --git a/src/cmd/compile/internal/noder/noder.go b/src/cmd/compile/internal/noder/noder.go
index 2c021cc..4c7c9fc 100644
--- a/src/cmd/compile/internal/noder/noder.go
+++ b/src/cmd/compile/internal/noder/noder.go
@@ -46,8 +46,8 @@
 		noders[i] = &p
 
 		filename := filename
-		sem <- struct{}{}
 		go func() {
+			sem <- struct{}{}
 			defer func() { <-sem }()
 			defer close(p.err)
 			fbase := syntax.NewFileBase(filename)