diff --git a/shard.yml b/shard.yml
index 25fe5ca..ea7660b 100644
--- a/shard.yml
+++ b/shard.yml
@@ -5,3 +5,5 @@ authors:
   - Luis Lavena <luislavena@gmail.com>
 
 license: MIT
+
+crystal: ">= 0.35.0"