diff --git a/src/connection.h b/src/connection.h
index b72886b..cafd196 100644
--- a/src/connection.h
+++ b/src/connection.h
@@ -106,9 +106,22 @@ public:
                      std::function<void(QMap<T, json>*)> cb) {    
         auto responses = new QMap<T, json>(); // zAddr -> list of responses for each call. 
         int totalSize = payloads.size();
+        if (totalSize == 0)
+            return;
+
+        // Keep track of all pending method calls, so as to prevent 
+        // any overlapping calls
+        static QMap<QString, bool> inProgress;
+
+        QString method = QString::fromStdString(payloadGenerator(payloads[0])["method"]);
+        if (inProgress.value(method, false)) {
+            qDebug() << "In progress batch, skipping";
+            return;
+        }
 
         for (auto item: payloads) {
             json payload = payloadGenerator(item);
+            inProgress[method] = true;
             
             QNetworkReply *reply = restclient->post(*request, QByteArray::fromStdString(payload.dump()));
 
@@ -148,7 +161,10 @@ public:
             // If all responses have arrived, return
             if (responses->size() == totalSize) {
                 waitTimer->stop();
+                
                 cb(responses);
+                inProgress[method] = false;
+
                 waitTimer->deleteLater();            
             }
         });
diff --git a/src/mainwindow.cpp b/src/mainwindow.cpp
index 34eb791..fbfcb01 100644
--- a/src/mainwindow.cpp
+++ b/src/mainwindow.cpp
@@ -16,7 +16,6 @@
 #include "senttxstore.h"
 #include "connection.h"
 
-#include "precompiled.h"
 
 using json = nlohmann::json;
 
diff --git a/src/rpc.h b/src/rpc.h
index c198532..42fa646 100644
--- a/src/rpc.h
+++ b/src/rpc.h
@@ -88,9 +88,6 @@ private:
     void getTransactions        (const std::function<void(json)>& cb);
     void getZAddresses          (const std::function<void(json)>& cb);
 
-    void handleConnectionError  (const QString& error);
-    void handleTxError          (const QString& error);
-
     Connection*                 conn                        = nullptr;
     QProcess*                   ezcashd                     = nullptr;