diff --git a/mining/simulator/config.go b/mining/simulator/config.go
index 65827307f..7e9ac6f85 100644
--- a/mining/simulator/config.go
+++ b/mining/simulator/config.go
@@ -28,6 +28,7 @@ type config struct {
 	CertificatePath  string `long:"cert" description:"Path to certificate accepted by JSON-RPC endpoint"`
 	DisableTLS       bool   `long:"notls" description:"Disable TLS"`
 	Verbose          bool   `long:"verbose" short:"v" description:"Enable logging of RPC requests"`
+	BlockDelay       uint64 `long:"block-delay" description:"Delay for block submission (in milliseconds)"`
 }
 
 func parseConfig() (*config, error) {
diff --git a/mining/simulator/main.go b/mining/simulator/main.go
index fe48ed61a..272701d56 100644
--- a/mining/simulator/main.go
+++ b/mining/simulator/main.go
@@ -29,7 +29,7 @@ func main() {
 	defer connManager.close()
 
 	spawn(func() {
-		err = mineLoop(connManager)
+		err = mineLoop(connManager, cfg.BlockDelay)
 		if err != nil {
 			panic(errors.Errorf("Error in main loop: %s", err))
 		}
diff --git a/mining/simulator/mineloop.go b/mining/simulator/mineloop.go
index eac0feb4a..0a051319e 100644
--- a/mining/simulator/mineloop.go
+++ b/mining/simulator/mineloop.go
@@ -50,7 +50,7 @@ func parseBlock(template *btcjson.GetBlockTemplateResult) (*util.Block, error) {
 	// parse rest of block
 	msgBlock := wire.NewMsgBlock(
 		wire.NewBlockHeader(template.Version, parentHashes, &daghash.Hash{},
-			acceptedIDMerkleRoot, utxoCommitment, uint32(bits), 0))
+			acceptedIDMerkleRoot, utxoCommitment, bits, 0))
 
 	for i, txResult := range append([]btcjson.GetBlockTemplateResultTx{*template.CoinbaseTxn}, template.Transactions...) {
 		reader := hex.NewDecoder(strings.NewReader(txResult.Data))
@@ -68,9 +68,9 @@ func parseBlock(template *btcjson.GetBlockTemplateResult) (*util.Block, error) {
 
 func solveBlock(block *util.Block, stopChan chan struct{}, foundBlock chan *util.Block) {
 	msgBlock := block.MsgBlock()
-	maxNonce := ^uint64(0) // 2^64 - 1
 	targetDifficulty := util.CompactToBig(msgBlock.Header.Bits)
-	for i := uint64(0); i < maxNonce; i++ {
+	initialNonce := random.Uint64()
+	for i := random.Uint64(); i != initialNonce-1; i++ {
 		select {
 		case <-stopChan:
 			return
@@ -152,13 +152,12 @@ func mineNextBlock(client *simulatorClient, foundBlock chan *util.Block, templat
 	go solveLoop(newTemplateChan, foundBlock, errChan)
 }
 
-func handleFoundBlock(client *simulatorClient, block *util.Block, templateStopChan chan struct{}) error {
-	templateStopChan <- struct{}{}
+func handleFoundBlock(client *simulatorClient, block *util.Block) error {
 	log.Infof("Found block %s with parents %s! Submitting to %s", block.Hash(), block.MsgBlock().Header.ParentHashes, client.Host())
 
 	err := client.SubmitBlock(block, &btcjson.SubmitBlockOptions{})
 	if err != nil {
-		return errors.Errorf("Error submitting block: %s", err)
+		return errors.Errorf("Error submitting block %s to %s: %s", block.Hash(), client.Host(), err)
 	}
 	return nil
 }
@@ -171,7 +170,7 @@ func getRandomClient(clients []*simulatorClient) *simulatorClient {
 	return clients[random.Int63n(clientsCount)]
 }
 
-func mineLoop(connManager *connectionManager) error {
+func mineLoop(connManager *connectionManager, blockDelay uint64) error {
 	errChan := make(chan error)
 
 	templateStopChan := make(chan struct{})
@@ -189,11 +188,16 @@ func mineLoop(connManager *connectionManager) error {
 				return
 			}
 			currentClient.notifyForNewBlocks = false
-			err := handleFoundBlock(currentClient, block, templateStopChan)
-			if err != nil {
-				errChan <- err
-				return
-			}
+			templateStopChan <- struct{}{}
+			spawn(func() {
+				if blockDelay != 0 {
+					time.Sleep(time.Duration(blockDelay) * time.Millisecond)
+				}
+				err := handleFoundBlock(currentClient, block)
+				if err != nil {
+					errChan <- err
+				}
+			})
 		}
 	})