diff --git a/lib/primitives/tx.js b/lib/primitives/tx.js
index 2849e039..231f0bbb 100644
--- a/lib/primitives/tx.js
+++ b/lib/primitives/tx.js
@@ -665,9 +665,11 @@ TX.prototype.signatureHashV1 = function signatureHashV1(index, prev, value, type
       if (!this.mutable)
         this._hashOutputs = outputs;
     }
-  } else if ((type & 0x1f) === hashType.SINGLE && index < this.outputs.length) {
-    const output = this.outputs[index];
-    outputs = digest.hash256(output.toRaw());
+  } else if ((type & 0x1f) === hashType.SINGLE) {
+    if (index < this.outputs.length) {
+      const output = this.outputs[index];
+      outputs = digest.hash256(output.toRaw());
+    }
   }
 
   const size = 156 + prev.getVarSize();