diff --git a/src/transaction_builder.js b/src/transaction_builder.js
index 8eee5d0..61aa17c 100644
--- a/src/transaction_builder.js
+++ b/src/transaction_builder.js
@@ -87,6 +87,7 @@ function expandInput (scriptSig, witnessStack) {
     witnessScript = witnessStack[witnessStack.length - 1]
     witnessScriptType = bscript.classifyOutput(witnessScript)
     p2wsh = true
+    witness = true
     if (scriptSig.length === 0) {
       prevOutScript = bscript.witnessScriptHash.output.encode(bcrypto.sha256(witnessScript))
       prevOutType = scriptTypes.P2WSH
@@ -112,6 +113,7 @@ function expandInput (scriptSig, witnessStack) {
     scriptType = witnessScriptType
     chunks = witnessStack.slice(0, -1)
   } else if (classifyWitness === scriptTypes.P2WPKH) {
+    witness = true
     var key = witnessStack[witnessStack.length - 1]
     var keyHash = bcrypto.hash160(key)
     if (scriptSig.length === 0) {