diff --git a/src/Snap.cpp b/src/Snap.cpp
index eaabe2265..c31bad82d 100644
--- a/src/Snap.cpp
+++ b/src/Snap.cpp
@@ -37,7 +37,7 @@ TrackClip::~TrackClip()
 
 }
 
-SnapManager::SnapManager(TrackList *tracks,
+SnapManager::SnapManager(const TrackList *tracks,
                          const ZoomInfo *zoomInfo,
                          const TrackClipArray *clipExclusions,
                          const TrackArray *trackExclusions,
@@ -102,8 +102,8 @@ void SnapManager::Reinit()
    // Add a SnapPoint at t=0
    mSnapPoints.push_back(SnapPoint{});
 
-   TrackListIterator iter(mTracks);
-   for (Track *track = iter.First();  track; track = iter.Next())
+   TrackListConstIterator iter(mTracks);
+   for (const Track *track = iter.First();  track; track = iter.Next())
    {
       if (mTrackExclusions &&
           mTrackExclusions->end() !=
diff --git a/src/Snap.h b/src/Snap.h
index bb9b6d6c9..9648375c4 100644
--- a/src/Snap.h
+++ b/src/Snap.h
@@ -73,7 +73,7 @@ using SnapPointArray = std::vector < SnapPoint > ;
 class SnapManager
 {
 public:
-   SnapManager(TrackList *tracks,
+   SnapManager(const TrackList *tracks,
                const ZoomInfo *zoomInfo,
                const TrackClipArray *clipExclusions = NULL,
                const TrackArray *trackExclusions = NULL,
@@ -112,7 +112,7 @@ private:
 private:
 
    const AudacityProject *mProject;
-   TrackList *mTracks;
+   const TrackList *mTracks;
    const TrackClipArray *mClipExclusions;
    const TrackArray *mTrackExclusions;
    const ZoomInfo *mZoomInfo;