diff --git a/src/qt/guiutil.cpp b/src/qt/guiutil.cpp
--- a/src/qt/guiutil.cpp
+++ b/src/qt/guiutil.cpp
@@ -6,6 +6,7 @@
 
 #include "bitcoinaddressvalidator.h"
 #include "bitcoinunits.h"
+#include "cashaddr.h"
 #include "qvalidatedlineedit.h"
 #include "walletmodel.h"
 
@@ -16,6 +17,7 @@
 #include "script/script.h"
 #include "script/standard.h"
 #include "util.h"
+#include "utilstrencodings.h"
 
 #ifdef WIN32
 #ifdef _WIN32_WINNT
@@ -115,13 +117,12 @@
 
 // Generate a dummy address with invalid CRC, starting with the network prefix.
 static std::string DummyAddress(const CChainParams &params) {
-    std::vector<unsigned char> sourcedata =
-        params.Base58Prefix(CChainParams::PUBKEY_ADDRESS);
-    sourcedata.insert(sourcedata.end(), dummydata,
-                      dummydata + sizeof(dummydata));
+    std::vector<uint8_t> sourcedata(dummydata, dummydata + sizeof(dummydata));
     for (int i = 0; i < 256; ++i) { // Try every trailing byte
-        std::string s = EncodeBase58(sourcedata.data(),
-                                     sourcedata.data() + sourcedata.size());
+
+        std::vector<uint8_t> data;
+        ConvertBits<8, 5, true>(data, begin(sourcedata), end(sourcedata));
+        std::string s = cashaddr::Encode(params.CashAddrHRP(), data);
         if (!IsValidDestinationString(s)) {
             return s;
         }