diff --git a/dev/snippets/config/templates/freeform.tmpl b/dev/snippets/config/templates/freeform.tmpl
index 704c42126c..739cc0a2ed 100644
--- a/dev/snippets/config/templates/freeform.tmpl
+++ b/dev/snippets/config/templates/freeform.tmpl
@@ -1,4 +1,5 @@
 /// Flutter code sample for {{element}}
+// @dart = 2.9
 
 {{description}}