diff --git a/mermaid.go b/mermaid.go
index fc5e163..ea8940f 100644
--- a/mermaid.go
+++ b/mermaid.go
@@ -63,7 +63,7 @@ func diagram(g *Graph, diagramType string, orientation int) string {
 	diagramGraph(g, sb)
 	for _, id := range g.sortedSubgraphsKeys() {
 		each := g.subgraphs[id]
-		fmt.Fprintf(sb, "subgraph %s;\n", id)
+		fmt.Fprintf(sb, "subgraph %s [%s];\n", id, each.attributes["label"])
 		diagramGraph(each, sb)
 		fmt.Fprintln(sb, "end;")
 	}
diff --git a/mermaid_test.go b/mermaid_test.go
index 7e4f1a0..16e5b7c 100644
--- a/mermaid_test.go
+++ b/mermaid_test.go
@@ -88,12 +88,12 @@ func TestMermaidSubgraph(t *testing.T) {
 	sub1.Node("a1").Edge(sub1.Node("a2"))
 	sub2 := di.Subgraph("two")
 	sub2.Node("b1").Edge(sub2.Node("b2"))
-	sub3 := di.Subgraph("three")
+	sub3 := di.Subgraph("THREE").Label("three")
 	sub3.Node("c1").Edge(sub3.Node("c2"))
 
 	sub3.Node("c1").Edge(sub1.Node("a2"))
 	mf := MermaidFlowchart(di, MermaidLeftToRight)
-	if got, want := flatten(mf), `flowchart LR;n8-->n3;subgraph one;n2("a1");n3("a2");n2-->n3;end;subgraph three;n8("c1");n9("c2");n8-->n9;end;subgraph two;n5("b1");n6("b2");n5-->n6;end;`; got != want {
+	if got, want := flatten(mf), `flowchart LR;n8-->n3;subgraph THREE [three];n8("c1");n9("c2");n8-->n9;end;subgraph one [one];n2("a1");n3("a2");n2-->n3;end;subgraph two [two];n5("b1");n6("b2");n5-->n6;end;`; got != want {
 		t.Errorf("got [%[1]v:%[1]T] want [%[2]v:%[2]T]", got, want)
 	}
 }