diff --git a/shard.yml b/shard.yml
index 27fbeb8..8ee0d91 100644
--- a/shard.yml
+++ b/shard.yml
@@ -1,12 +1,12 @@
 name: callback
-version: 0.6.3
+version: 0.9.2
 
 authors:
   - mosop
 
 license: MIT
 
-crsytal: 0.23.1
+crystal: ">= 0.26.0, < 2.0"
 
 development_dependencies:
   stdio:
diff --git a/src/callback.cr b/src/callback.cr
index c6339be..655f089 100644
--- a/src/callback.cr
+++ b/src/callback.cr
@@ -1,2 +1 @@
-require "./version"
 require "./callback/*"
diff --git a/src/callback/result_set.cr b/src/callback/result_set.cr
index af0c2e7..eaf85b0 100644
--- a/src/callback/result_set.cr
+++ b/src/callback/result_set.cr
@@ -25,9 +25,9 @@ module Callback
       named.has_key?(name.to_s)
     end
 
-    def each
-      named.each do |k, v|
-        yield k, v
+    def each(&block : T -> _)
+      named.each do |_, v|
+        yield v
       end
     end
   end
diff --git a/src/version.cr b/src/callback/version.cr
similarity index 50%
rename from src/version.cr
rename to src/callback/version.cr
index f2555a2..a4f6dbb 100644
--- a/src/version.cr
+++ b/src/callback/version.cr
@@ -1,3 +1,3 @@
 module Callback
-  VERSION = "0.6.3"
+  VERSION = "0.7.1"
 end