diff --git a/src/effects/TwoPassSimpleMono.cpp b/src/effects/TwoPassSimpleMono.cpp
index 42efb7b8c..b3fdd614c 100644
--- a/src/effects/TwoPassSimpleMono.cpp
+++ b/src/effects/TwoPassSimpleMono.cpp
@@ -35,7 +35,8 @@ bool EffectTwoPassSimpleMono::Process()
       const_cast<AudacityProject*>( FindProject() ) );
    for (auto track : mOutputTracks->Selected< WaveTrack >()) {
       mWorkTracks->Add(track->EmptyCopy())->ConvertToSampleFormat(floatSample);
-      mWorkTracks->back()->InsertSilence(0, mT0);
+      if( mT0 > 0 )
+         mWorkTracks->back()->InsertSilence(0, mT0);
    }
 
    mTrackLists[0] = &mOutputTracks;