diff --git a/src/radix/node.cr b/src/radix/node.cr
index 54ab2e3..2512327 100644
--- a/src/radix/node.cr
+++ b/src/radix/node.cr
@@ -88,8 +88,7 @@ module Radix
     # node.priority
     # # => 6
     # ```
-    def key=(value : String)
-      @key = value
+    def key=(@key : String)
       @priority = compute_priority
     end