diff --git a/src/pkg/runtime/debug/stack_test.go b/src/pkg/runtime/debug/stack_test.go
index f33f5072b4..bbd662618f 100644
--- a/src/pkg/runtime/debug/stack_test.go
+++ b/src/pkg/runtime/debug/stack_test.go
@@ -36,7 +36,7 @@ func (t T) method() []byte {
 func TestStack(t *testing.T) {
 	b := T(0).method()
 	lines := strings.Split(string(b), "\n")
-	if len(lines) <= 6 {
+	if len(lines) < 6 {
 		t.Fatal("too few lines")
 	}
 	n := 0