diff --git a/.tool-versions b/.tool-versions
new file mode 100644
index 0000000..6fc654b
--- /dev/null
+++ b/.tool-versions
@@ -0,0 +1 @@
+crystal 1.2.0
diff --git a/src/apatite/vector.cr b/src/apatite/vector.cr
index 758fc22..413ad3f 100644
--- a/src/apatite/vector.cr
+++ b/src/apatite/vector.cr
@@ -12,7 +12,7 @@ module Apatite
 
     protected getter elements : Array(T)
 
-    delegate :each, to: @elements
+    delegate :each, :size, to: @elements
 
     private def initialize(array : Indexable(T))
       {% raise "Vectors must be one type only" if T.union? %}