diff --git a/sdrbase/dsp/scopevis.cpp b/sdrbase/dsp/scopevis.cpp
index d70723324..dc208cb7c 100644
--- a/sdrbase/dsp/scopevis.cpp
+++ b/sdrbase/dsp/scopevis.cpp
@@ -91,7 +91,7 @@ void ScopeVis::feed(SampleVector::const_iterator begin, SampleVector::const_iter
 							m_triggerPoint = begin;
                             // fill beginning of m_trace with delayed samples from the trace memory FIFO. Increment m_fill accordingly.
                             if (m_triggerPre) { // do this process only if there is a pre-trigger delay
-                                std::copy(m_traceback.end() - m_triggerPre, m_traceback.end() - 1, m_trace.begin());
+                                std::copy(m_traceback.end() - m_triggerPre - 1, m_traceback.end() - 1, m_trace.begin());
                                 m_fill = m_triggerPre; // Increment m_fill accordingly (from 0).
                             }
 							break;
diff --git a/sdrbase/gui/glscopegui.ui b/sdrbase/gui/glscopegui.ui
index 5c6216310..5cce46ec3 100644
--- a/sdrbase/gui/glscopegui.ui
+++ b/sdrbase/gui/glscopegui.ui
@@ -730,7 +730,7 @@
         <string>Pre-trigger delay</string>
        </property>
        <property name="maximum">
-        <number>100</number>
+        <number>99</number>
        </property>
        <property name="pageStep">
         <number>1</number>