diff --git a/app/utils/cps/bignumber.js b/app/utils/cps/bignumber.js
index 4fd3f55..0a4f893 100644
--- a/app/utils/cps/bignumber.js
+++ b/app/utils/cps/bignumber.js
@@ -5,8 +5,10 @@ export default function(dependentKey, converterMethod) {
   return computed(dependentKey, {
     get () {
       let value = this.get(dependentKey);
-      if (value) {
-        return this.get(dependentKey)[converterMethod]();
+      if (value && ethers.utils.isBigNumber(value)) {
+        return value[converterMethod]();
+      } else {
+        return value;
       }
     },
     set (key, value) {