diff --git a/web/cashtab/config/webpack.config.js b/web/cashtab/config/webpack.config.js
--- a/web/cashtab/config/webpack.config.js
+++ b/web/cashtab/config/webpack.config.js
@@ -280,6 +280,7 @@
                         },
                         mangle: {
                             safari10: true,
+                            reserved: ['BigInteger'],
                         },
                         // Added for profiling in devtools
                         keep_classnames: isEnvProductionProfile,
diff --git a/web/cashtab/src/utils/__tests__/cashMethods.test.js b/web/cashtab/src/utils/__tests__/cashMethods.test.js
--- a/web/cashtab/src/utils/__tests__/cashMethods.test.js
+++ b/web/cashtab/src/utils/__tests__/cashMethods.test.js
@@ -271,7 +271,6 @@
     );
 
     const txBuilderResponse = signUtxosByAddress(
-        BCH,
         mockSingleInputUtxo,
         wallet,
         outputObj,
@@ -339,7 +338,6 @@
     );
 
     const txBuilderResponse = signUtxosByAddress(
-        BCH,
         mockSingleInputUtxo,
         wallet,
         outputObj,
diff --git a/web/cashtab/src/utils/cashMethods.js b/web/cashtab/src/utils/cashMethods.js
--- a/web/cashtab/src/utils/cashMethods.js
+++ b/web/cashtab/src/utils/cashMethods.js
@@ -152,7 +152,7 @@
     return Bitcoin.ECPair.fromWIF(wif, xecBitcoinJSLib);
 };
 
-export const signUtxosByAddress = (BCH, inputUtxos, wallet, txBuilder) => {
+export const signUtxosByAddress = (inputUtxos, wallet, txBuilder) => {
     for (let i = 0; i < inputUtxos.length; i++) {
         const utxo = inputUtxos[i];
         const accounts = [wallet.Path245, wallet.Path145, wallet.Path1899];
@@ -161,7 +161,7 @@
             .filter(acc => acc.cashAddress === utxo.address)
             .pop().fundingWif;
 
-        const utxoECPair = BCH.ECPair.fromWIF(wif);
+        const utxoECPair = getECPairFromWIF(wif);
 
         txBuilder.sign(
             i,
@@ -714,7 +714,7 @@
     }
 
     // Sign each XEC UTXO being consumed and refresh transactionBuilder
-    txBuilder = signUtxosByAddress(BCH, inputUtxos, wallet, txBuilder);
+    txBuilder = signUtxosByAddress(inputUtxos, wallet, txBuilder);
 
     let hex;
     try {