diff --git a/lib/primitives/mtx.js b/lib/primitives/mtx.js
index 9c15ed0b..b6c1f744 100644
--- a/lib/primitives/mtx.js
+++ b/lib/primitives/mtx.js
@@ -349,7 +349,7 @@ MTX.prototype.scriptVector = function scriptVector(prev, vector, ring) {
 
   // P2PK
   if (prev.isPubkey()) {
-    if (!utils.equal(prev.get(1), ring.publicKey))
+    if (!utils.equal(prev.get(0), ring.publicKey))
       return false;
 
     vector.set(0, opcodes.OP_0);