diff --git a/src/demod/DemodulatorThread.h b/src/demod/DemodulatorThread.h
index c713596..bc4e2b0 100644
--- a/src/demod/DemodulatorThread.h
+++ b/src/demod/DemodulatorThread.h
@@ -25,8 +25,8 @@ public:
 
     void onBindOutput(std::string name, ThreadQueueBasePtr threadQueue);
     
-    void run();
-    void terminate();
+    virtual void run();
+    virtual void terminate();
     
     void setMuted(bool state);
     bool isMuted();
diff --git a/src/process/FFTVisualDataThread.cpp b/src/process/FFTVisualDataThread.cpp
index e302c1b..0dd398e 100644
--- a/src/process/FFTVisualDataThread.cpp
+++ b/src/process/FFTVisualDataThread.cpp
@@ -84,3 +84,9 @@ void FFTVisualDataThread::run() {
 //    std::cout << "FFT visual data thread done." << std::endl;
 }
 
+void FFTVisualDataThread::terminate() {
+    IOThread::terminate();
+    fftDistrib.flushQueues();
+    wproc.flushQueues();
+}
+
diff --git a/src/process/FFTVisualDataThread.h b/src/process/FFTVisualDataThread.h
index 70b31a9..549950b 100644
--- a/src/process/FFTVisualDataThread.h
+++ b/src/process/FFTVisualDataThread.h
@@ -17,6 +17,8 @@ public:
     SpectrumVisualProcessor *getProcessor();
     
     virtual void run();
+
+    virtual void terminate();
     
 protected:
     FFTDataDistributor fftDistrib;
diff --git a/src/process/SpectrumVisualDataThread.cpp b/src/process/SpectrumVisualDataThread.cpp
index 1e954a2..5841f52 100644
--- a/src/process/SpectrumVisualDataThread.cpp
+++ b/src/process/SpectrumVisualDataThread.cpp
@@ -28,3 +28,7 @@ void SpectrumVisualDataThread::run() {
 //    std::cout << "Spectrum visual data thread done." << std::endl;
 }
 
+void SpectrumVisualDataThread::terminate() {
+    IOThread::terminate();
+    sproc.flushQueues();
+}
\ No newline at end of file
diff --git a/src/process/SpectrumVisualDataThread.h b/src/process/SpectrumVisualDataThread.h
index c6efc6c..0c3eccf 100644
--- a/src/process/SpectrumVisualDataThread.h
+++ b/src/process/SpectrumVisualDataThread.h
@@ -13,6 +13,8 @@ public:
     SpectrumVisualProcessor *getProcessor();
     
     virtual void run();
+
+    virtual void terminate();
     
 protected:
     SpectrumVisualProcessor sproc;
diff --git a/src/process/VisualProcessor.h b/src/process/VisualProcessor.h
index 13e8966..6fae52a 100644
--- a/src/process/VisualProcessor.h
+++ b/src/process/VisualProcessor.h
@@ -82,6 +82,17 @@ public:
             outputs.erase(i);
         }
     }
+    //Flush all queues, either input or outputs clearing their accumulated messages.
+    //this is purposefully non-blocking call.
+    void flushQueues() {
+        //DO NOT take the busy_update, we want a never blocking op how imperfect it could be.
+        input->flush();
+
+        for (auto single_output : outputs) {
+
+            single_output->flush();
+        }
+    }
     
     //Call process() repeateadly until all available 'input' data is consumed.
     void run() {
diff --git a/src/sdr/SoapySDRThread.cpp b/src/sdr/SoapySDRThread.cpp
index ecd1d54..7513612 100644
--- a/src/sdr/SoapySDRThread.cpp
+++ b/src/sdr/SoapySDRThread.cpp
@@ -564,6 +564,15 @@ void SDRThread::run() {
     std::cout << "SDR thread done." << std::endl;
 }
 
+void SDRThread::terminate() {
+    IOThread::terminate();
+
+    SDRThreadIQDataQueuePtr iqDataOutQueue = std::static_pointer_cast<SDRThreadIQDataQueue>(getOutputQueue("IQDataOutput"));
+
+    if (iqDataOutQueue != nullptr) {
+        iqDataOutQueue->flush();
+    }
+}
 
 SDRDeviceInfo *SDRThread::getDevice() {
     return deviceInfo.load();
diff --git a/src/sdr/SoapySDRThread.h b/src/sdr/SoapySDRThread.h
index 83472ff..c72c5a9 100644
--- a/src/sdr/SoapySDRThread.h
+++ b/src/sdr/SoapySDRThread.h
@@ -61,6 +61,7 @@ public:
     enum SDRThreadState { SDR_THREAD_MESSAGE, SDR_THREAD_INITIALIZED, SDR_THREAD_FAILED};
     
     virtual void run();
+    virtual void terminate();
 
     SDRDeviceInfo *getDevice();
     void setDevice(SDRDeviceInfo *dev);