diff --git a/lib/primitives/mtx.js b/lib/primitives/mtx.js
index f8a1c6da..46f8f335 100644
--- a/lib/primitives/mtx.js
+++ b/lib/primitives/mtx.js
@@ -1371,7 +1371,7 @@ MTX.prototype.getJSON = function getJSON(network) {
  */
 
 MTX.fromJSON = function fromJSON(json) {
-  return new MTX().fromJSON(JSON);
+  return new MTX().fromJSON(json);
 };
 
 /**