Index: qa/rpc-tests/walletbackup.py
===================================================================
--- qa/rpc-tests/walletbackup.py
+++ qa/rpc-tests/walletbackup.py
@@ -199,6 +199,17 @@
         assert_equal(self.nodes[1].getbalance(), balance1)
         assert_equal(self.nodes[2].getbalance(), balance2)
 
+        # Backup to source wallet file must fail
+        sourcePaths = [
+            tmpdir + "/node0/regtest/wallet.dat",
+            tmpdir + "/node0/./regtest/wallet.dat",
+            tmpdir + "/node0/regtest/",
+            tmpdir + "/node0/regtest"]
+
+        for sourcePath in sourcePaths:
+            assert_raises_jsonrpc(-4, "backup failed",
+                    self.nodes[0].backupwallet, sourcePath)
+
 
 if __name__ == '__main__':
     WalletBackupTest().main()
Index: src/wallet/wallet.cpp
===================================================================
--- src/wallet/wallet.cpp
+++ src/wallet/wallet.cpp
@@ -4399,6 +4399,14 @@
                 }
 
                 try {
+
+                    if (boost::filesystem::equivalent(pathSrc, pathDest)) {
+                        LogPrintf("cannot backup to wallet source file %s\n",
+                                  pathDest.string());
+                        return false;
+
+                    }
+
 #if BOOST_VERSION >= 104000
                     boost::filesystem::copy_file(
                         pathSrc, pathDest,