diff --git a/keymap/vim.js b/keymap/vim.js
index b2c404d45ea15b13242efb4fe81c4d63bd1c3c6e..1f5d949d9379f9f907067191e12ddc53e8fff6cb 100644
--- a/keymap/vim.js
+++ b/keymap/vim.js
@@ -958,7 +958,7 @@
      * for a reference implementation.
      */
     function defineRegister(name, register) {
-      var registers = vimGlobalState.registerController.registers[name];
+      var registers = vimGlobalState.registerController.registers;
       if (!name || name.length != 1) {
         throw Error('Register name must be 1 character');
       }