diff --git a/libaegisub/common/karaoke_matcher.cpp b/libaegisub/common/karaoke_matcher.cpp
index 8d8477b4a7..5ac79ee755 100644
--- a/libaegisub/common/karaoke_matcher.cpp
+++ b/libaegisub/common/karaoke_matcher.cpp
@@ -213,6 +213,7 @@ namespace agi {
 void KaraokeMatcher::SetInputData(std::vector<ass::KaraokeSyllable>&& src, std::string&& dst) {
 	syllables = std::move(src);
 	matched_groups.clear();
+	character_positions.clear();
 	src_start = 0;
 	src_len = syllables.size() ? 1 : 0;
 
@@ -239,7 +240,7 @@ std::string KaraokeMatcher::GetOutputLine() const {
 }
 
 bool KaraokeMatcher::IncreaseSourceMatch() {
-	if (src_start + src_len < syllables.size()) { // FIXME: off-by-one?
+	if (src_start + src_len < syllables.size()) {
 		++src_len;
 		return true;
 	}
diff --git a/src/dialog_kara_timing_copy.cpp b/src/dialog_kara_timing_copy.cpp
index b7cd4ce8d9..115a860b8d 100644
--- a/src/dialog_kara_timing_copy.cpp
+++ b/src/dialog_kara_timing_copy.cpp
@@ -82,9 +82,9 @@ class KaraokeLineMatchDisplay final : public wxControl {
 	std::string GetOutputLine() const { return matcher.GetOutputLine(); }
 
 	/// Number of syllables not yet matched from source
-	size_t GetRemainingSource() const { return matcher.UnmatchedSource().size(); }
+	size_t GetRemainingSource() const { return matcher.UnmatchedSource().size() + matcher.CurrentSourceSelection().size(); }
 	/// Number of characters not yet matched from destination
-	size_t GetRemainingDestination() const { return matcher.UnmatchedDestination().size(); }
+	size_t GetRemainingDestination() const { return matcher.UnmatchedDestination().size() + matcher.CurrentDestinationSelection().size(); }
 
 	// Adjust source and destination match lengths
 	void IncreaseSourceMatch();
@@ -301,7 +301,8 @@ void KaraokeLineMatchDisplay::OnPaint(wxPaintEvent &)
 void KaraokeLineMatchDisplay::SetInputData(AssDialogue *src, AssDialogue *dst)
 {
 	last_total_matchgroup_render_width = 0;
-	matcher.SetInputData(ParseKaraokeSyllables(src), dst->GetStrippedText());
+	matcher.SetInputData(ParseKaraokeSyllables(src), dst ? dst->GetStrippedText() : "");
+	Refresh(true);
 }
 
 void KaraokeLineMatchDisplay::IncreaseSourceMatch()