diff --git a/shard.yml b/shard.yml
index e1b4b6b..dc58c04 100644
--- a/shard.yml
+++ b/shard.yml
@@ -18,6 +18,6 @@ targets:
   zipstream:
     main: src/zipstream_cli.cr
 
-crystal: 1.9.0
+crystal: 1.9.1
 
 license: MIT