diff --git a/src/cmd/compile/internal/ssa/html.go b/src/cmd/compile/internal/ssa/html.go
index 5c23320680..44e4e19b77 100644
--- a/src/cmd/compile/internal/ssa/html.go
+++ b/src/cmd/compile/internal/ssa/html.go
@@ -379,7 +379,7 @@ func (b *Block) HTML() string {
 
 func (b *Block) LongHTML() string {
 	// TODO: improve this for HTML?
-	s := b.Kind.String()
+	s := fmt.Sprintf("<span class=\"%s ssa-block\">%s</span>", html.EscapeString(b.String()), html.EscapeString(b.Kind.String()))
 	if b.Control != nil {
 		s += fmt.Sprintf(" %s", b.Control.HTML())
 	}