diff --git a/src/cmd/compile/internal/ssa/html.go b/src/cmd/compile/internal/ssa/html.go
index c51ea02..b7d5f91 100644
--- a/src/cmd/compile/internal/ssa/html.go
+++ b/src/cmd/compile/internal/ssa/html.go
@@ -484,7 +484,7 @@
 func (x ByTopo) Less(i, j int) bool {
 	a := x[i]
 	b := x[j]
-	if a.Filename == a.Filename {
+	if a.Filename == b.Filename {
 		return a.StartLineno < b.StartLineno
 	}
 	return a.Filename < b.Filename