diff --git a/src/go/types/hilbert_test.go b/src/go/types/hilbert_test.go
index 41d1a2a7dc..9783ce6dc9 100644
--- a/src/go/types/hilbert_test.go
+++ b/src/go/types/hilbert_test.go
@@ -52,7 +52,7 @@ func program(n int, out string) []byte {
 
 	g.p(`// Code generated by: go test -run=Hilbert -H=%d -out=%q. DO NOT EDIT.
 
-// +build ignore
+// +`+`build ignore
 
 // This program tests arbitrary precision constant arithmetic
 // by generating the constant elements of a Hilbert matrix H,