diff --git a/sdrbase/dsp/scopevisng.cpp b/sdrbase/dsp/scopevisng.cpp
index f2196596e..25189c9f2 100644
--- a/sdrbase/dsp/scopevisng.cpp
+++ b/sdrbase/dsp/scopevisng.cpp
@@ -213,6 +213,7 @@ void ScopeVisNG::processMemoryTrace()
         SampleVector::const_iterator mend = m_traceDiscreteMemory.at(m_currentTraceMemoryIndex).m_endPoint;
         SampleVector::const_iterator mbegin = mend - m_traceSize;
         SampleVector::const_iterator mbegin_tb = mbegin - m_maxTraceDelay;
+        m_nbSamples = m_traceSize + m_maxTraceDelay;
 
         processTraces(mbegin_tb, mbegin, true); // traceback
         processTraces(mbegin, mend, false);
@@ -658,7 +659,7 @@ bool ScopeVisNG::handleMessage(const Message& message)
             m_currentTraceMemoryIndex = memoryIndex;
 
             if (m_currentTraceMemoryIndex > 0) {
-
+                processMemoryTrace();
             }
         }
     }
diff --git a/sdrbase/dsp/scopevisng.h b/sdrbase/dsp/scopevisng.h
index 96f6ec917..a1502ee67 100644
--- a/sdrbase/dsp/scopevisng.h
+++ b/sdrbase/dsp/scopevisng.h
@@ -433,7 +433,7 @@ private:
             return new MsgScopeVisNGMemoryTrace(memoryIndex);
         }
 
-        bool getMemoryIndex() const { return m_memoryIndex; }
+        uint32_t getMemoryIndex() const { return m_memoryIndex; }
 
     private:
         uint32_t m_memoryIndex;