diff --git a/src/containers/AddressBook.tsx b/src/containers/AddressBook.tsx
index 745eebd..76e985a 100644
--- a/src/containers/AddressBook.tsx
+++ b/src/containers/AddressBook.tsx
@@ -91,7 +91,7 @@ export const AddressBook = () => {
         try {
             const [, prefix] = ss58Decode(address)
             if (prefix !== 1995 && prefix !== 1996) {
-                throw ""
+                throw new Error("bad prefix")
             }
         } catch (e) {
             setError("Incorrect Ghost or Casper address provided")